diff --git a/src/args.jl b/src/args.jl
index a5f043b4..f721e754 100644
--- a/src/args.jl
+++ b/src/args.jl
@@ -232,6 +232,7 @@ const _bar_width = 0.8
 
 const _series_defaults = KW(
     :label             => "AUTO",
+    :colorbar_entry    => true,
     :seriescolor       => :auto,
     :seriesalpha       => nothing,
     :seriestype        => :path,
@@ -1509,19 +1510,19 @@ function has_black_border_for_default(st::Symbol)
     like_histogram(st) || st in (:hexbin, :bar, :shape)
 end
 
-
-# converts a symbol or string into a colorant (Colors.RGB), and assigns a color automatically
-function getSeriesRGBColor(c, sp::Subplot, n::Int)
+# converts a symbol or string into a Colorant or ColorGradient
+# and assigns a color automatically
+function get_series_color(c, sp::Subplot, n::Int, seriestype)
     if c == :auto
-        c = autopick(sp[:color_palette], n)
+        c = like_surface(seriestype) ? cgrad() : autopick(sp[:color_palette], n)
     elseif isa(c, Int)
         c = autopick(sp[:color_palette], c)
     end
     plot_color(c)
 end
 
-function getSeriesRGBColor(c::AbstractArray, sp::Subplot, n::Int)
-    map(x->getSeriesRGBColor(x, sp, n), c)
+function get_series_color(c::AbstractArray, sp::Subplot, n::Int, seriestype)
+    map(x->get_series_color(x, sp, n), c, seriestype)
 end
 
 function ensure_gradient!(plotattributes::KW, csym::Symbol, asym::Symbol)
@@ -1566,21 +1567,23 @@ function _update_series_attributes!(plotattributes::KW, plt::Plot, sp::Subplot)
     end
 
     # update series color
-    plotattributes[:seriescolor] = getSeriesRGBColor(plotattributes[:seriescolor], sp, plotIndex)
+    scolor = plotattributes[:seriescolor] 
+    stype = plotattributes[:seriestype]
+    plotattributes[:seriescolor] = scolor = get_series_color(scolor, sp, plotIndex, stype)
 
     # update other colors
     for s in (:line, :marker, :fill)
         csym, asym = Symbol(s,:color), Symbol(s,:alpha)
         plotattributes[csym] = if plotattributes[csym] == :auto
-            plot_color(if has_black_border_for_default(plotattributes[:seriestype]) && s == :line
+            plot_color(if has_black_border_for_default(stype) && s == :line
                 sp[:foreground_color_subplot]
             else
-                plotattributes[:seriescolor]
+                scolor
             end)
         elseif plotattributes[csym] == :match
-            plot_color(plotattributes[:seriescolor])
+            plot_color(scolor)
         else
-            getSeriesRGBColor(plotattributes[csym], sp, plotIndex)
+            get_series_color(plotattributes[csym], sp, plotIndex, stype)
         end
     end
 
@@ -1588,9 +1591,9 @@ function _update_series_attributes!(plotattributes::KW, plt::Plot, sp::Subplot)
     plotattributes[:markerstrokecolor] = if plotattributes[:markerstrokecolor] == :match
         plot_color(sp[:foreground_color_subplot])
     elseif plotattributes[:markerstrokecolor] == :auto
-        getSeriesRGBColor(plotattributes[:markercolor], sp, plotIndex)
+        get_series_color(plotattributes[:markercolor], sp, plotIndex, stype)
     else
-        getSeriesRGBColor(plotattributes[:markerstrokecolor], sp, plotIndex)
+        get_series_color(plotattributes[:markerstrokecolor], sp, plotIndex, stype)
     end
 
     # if marker_z, fill_z or line_z are set, ensure we have a gradient
diff --git a/src/backends.jl b/src/backends.jl
index 8f24be72..8cb4c0ce 100644
--- a/src/backends.jl
+++ b/src/backends.jl
@@ -332,7 +332,7 @@ const _gr_attr = merge_with_base_supported([
     :guidefontfamily, :guidefontsize, :guidefonthalign, :guidefontvalign,
     :guidefontrotation, :guidefontcolor,
     :grid, :gridalpha, :gridstyle, :gridlinewidth,
-    :legend, :legendtitle, :colorbar, :colorbar_title,
+    :legend, :legendtitle, :colorbar, :colorbar_title, :colorbar_entry,
     :fill_z, :line_z, :marker_z, :levels,
     :ribbon, :quiver,
     :orientation,
@@ -386,7 +386,7 @@ const _plotly_attr = merge_with_base_supported([
     :guide, :lims, :ticks, :scale, :flip, :rotation,
     :tickfont, :guidefont, :legendfont,
     :grid, :gridalpha, :gridlinewidth,
-    :legend, :colorbar, :colorbar_title,
+    :legend, :colorbar, :colorbar_title, :colorbar_entry,
     :marker_z, :fill_z, :line_z, :levels,
     :ribbon, :quiver,
     :orientation,
@@ -511,7 +511,7 @@ const _pyplot_attr = merge_with_base_supported([
     :tickfontfamily, :tickfontsize, :tickfontcolor,
     :guidefontfamily, :guidefontsize, :guidefontcolor,
     :grid, :gridalpha, :gridstyle, :gridlinewidth,
-    :legend, :legendtitle, :colorbar,
+    :legend, :legendtitle, :colorbar, :colorbar_title, :colorbar_entry,
     :marker_z, :line_z, :fill_z,
     :levels,
     :ribbon, :quiver, :arrow,
@@ -524,7 +524,6 @@ const _pyplot_attr = merge_with_base_supported([
     :clims,
     :inset_subplots,
     :dpi,
-    :colorbar_title,
     :stride,
     :framestyle,
     :tick_direction,
diff --git a/src/backends/gr.jl b/src/backends/gr.jl
index be38832f..db395837 100644
--- a/src/backends/gr.jl
+++ b/src/backends/gr.jl
@@ -415,24 +415,96 @@ function gr_set_viewport_polar()
     r
 end
 
+struct GRColorbar
+    gradient::Ref{Union{Series,Nothing}}
+    fill::Ref{Union{Series,Nothing}}
+    lines::Ref{Union{Series,Nothing}}
+    GRColorbar() = new(nothing,nothing,nothing)
+end
+
+function gr_update_colorbar!(cbar::GRColorbar, series::Series)
+    style = colorbar_style(series)
+    style === nothing && return
+    ref = style == cbar_gradient ? cbar.gradient :
+          style == cbar_fill ? cbar.fill :
+          style == cbar_lines ? cbar.lines :
+          error("Unknown colorbar style: $style.")
+    if ref[] !== nothing
+        @warn "Overwriting colorbar entry"
+    end
+    ref[] = series
+end
+
+function gr_contour_levels(series::Series, clims)
+    levels = contour_levels(series, clims)
+    if isfilledcontour(series)
+        # GR implicitly uses the maximal z value as the highest level
+        levels = levels[1:end-1]
+    end
+    levels
+end    
+    
+function gr_colorbar_colors(series::Series, clims)
+    if iscontour(series)
+        levels = gr_contour_levels(series, clims)
+        if isfilledcontour(series)
+            # GR.contourf uses a color range according to supplied levels
+            zrange = ignorenan_extrema(levels)
+        else
+            # GR.contour uses a color range according to data range
+            zrange = clims
+        end
+        colors = 1000 .+ 255 .* (levels .- zrange[1]) ./ (zrange[2] - zrange[1])
+    else
+        colors = 1000:1255
+    end
+    round.(Int,colors)
+end
+
 # add the colorbar
-function gr_colorbar(sp::Subplot, clims, levels)
+function gr_draw_colorbar(cbar::GRColorbar, sp::Subplot, clims)
     GR.savestate()
     xmin, xmax = gr_xy_axislims(sp)[1:2]
     zmin, zmax = clims[1:2]
     gr_set_viewport_cmap(sp)
-    l = if levels === nothing
-       (1000:1255)'
-    elseif length(levels) > 1
-        min_level, max_level = ignorenan_minimum(levels), ignorenan_maximum(levels)
-        round.(Int32, 1000 .+ (levels .- min_level) ./ (max_level - min_level) .* 255)
-    else
-        Int32[1000, 1255]
-    end
     GR.setscale(0)
     GR.setwindow(xmin, xmax, zmin, zmax)
-    GR.cellarray(xmin, xmax, zmax, zmin, 1, length(l), l)
+    if (series = cbar.gradient[]) !== nothing
+        gr_set_gradient(series)
+        GR.cellarray(xmin, xmax, zmax, zmin, 1, 256, 1000:1255)
+    end
+
+    if (series = cbar.fill[]) !== nothing
+        gr_set_gradient(series)
+        GR.setfillintstyle(GR.INTSTYLE_SOLID)
+        levels = contour_levels(series, clims)
+        # GR implicitly uses the maximal z value as the highest level
+        if levels[end] < clims[2]
+            @warn("GR: highest contour level less than maximal z value is not supported.")
+            # replace levels, rather than assign to levels[end], to ensure type
+            # promotion in case levels is an integer array
+            levels = [levels[1:end-1]; clims[2]]
+        end
+        colors = gr_colorbar_colors(series, clims)
+        for (from, to, color) in zip(levels[1:end-1], levels[2:end], colors)
+            GR.setfillcolorind(color)
+            GR.fillrect( xmin, xmax, from, to )
+        end
+    end
+
+    if (series = cbar.lines[]) !== nothing
+        gr_set_gradient(series)
+        gr_set_line(get_linewidth(series), get_linestyle(series), get_linecolor(series, clims))
+        levels = contour_levels(series, clims)
+        colors = gr_colorbar_colors(series, clims)
+        for (line, color) in zip(levels, colors)
+            GR.setlinecolorind(color)
+            GR.polyline([xmin,xmax], [line,line] )
+        end
+    end
+    
     ztick = 0.5 * GR.tick(zmin, zmax)
+    gr_set_line(1, :solid, plot_color(:black))
     GR.axes(0, ztick, xmax, zmin, 0, 1, 0.005)
 
     gr_set_font(guidefont(sp[:yaxis]))
@@ -480,7 +552,7 @@ end
 const _gr_gradient_alpha = ones(256)
 
 function gr_set_gradient(c)
-    grad = c isa ColorGradient ? c : cgrad()
+    grad = _as_gradient(c)
     for (i,z) in enumerate(range(0, stop=1, length=256))
         c = grad[z]
         GR.setcolorrep(999+i, red(c), green(c), blue(c))
@@ -489,6 +561,21 @@ function gr_set_gradient(c)
     grad
 end
 
+function gr_set_gradient(series::Series)
+    st = series[:seriestype]
+    if st in (:surface, :heatmap) || isfilledcontour(series)
+        gr_set_gradient(series[:fillcolor])
+    elseif st in (:contour, :wireframe)
+        gr_set_gradient(series[:linecolor])
+    elseif series[:marker_z] != nothing
+        gr_set_gradient(series[:markercolor])
+    elseif series[:line_z] !=  nothing
+        gr_set_gradient(series[:linecolor])
+    elseif series[:fill_z] != nothing
+        gr_set_gradient(series[:fillcolor])
+    end
+end
+
 # this is our new display func... set up the viewport_canvas, compute bounding boxes, and display each subplot
 function gr_display(plt::Plot, fmt="")
     GR.clearws()
@@ -671,7 +758,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
     outside_ticks = false
     # calculate the colorbar limits once for a subplot
     clims = get_clims(sp)
-    clevels = nothing
+    cbar = GRColorbar()
 
     draw_axes = sp[:framestyle] != :none
     # axes_2d = true
@@ -695,8 +782,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
             data_lims = gr_xy_axislims(sp)
         end
 
-        # color levels overwritten by the last relevant series
-        hascolorbar(series) && (clevels = colorbar_levels(series, clims))
+        gr_update_colorbar!(cbar,series)
     end
 
     # set our plot area view
@@ -970,24 +1056,12 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
 
     for (idx, series) in enumerate(series_list(sp))
         st = series[:seriestype]
-
+        
         # update the current stored gradient
-        if st in (:surface, :heatmap) ||
-                (st == :contour && series[:fillrange] !== nothing)
-            gr_set_gradient(series[:fillcolor]) #, series[:fillalpha])
-        elseif st in (:contour, :wireframe)
-            gr_set_gradient(series[:linecolor])
-        elseif series[:marker_z] != nothing
-            series[:markercolor] = gr_set_gradient(series[:markercolor])
-        elseif series[:line_z] !=  nothing
-            series[:linecolor] = gr_set_gradient(series[:linecolor])
-        elseif series[:fill_z] != nothing
-            series[:fillcolor] = gr_set_gradient(series[:fillcolor])
-        end
+        gr_set_gradient(series)
 
         GR.savestate()
 
-
         # update the bounding window
         if ispolar(sp)
             gr_set_viewport_polar()
@@ -1053,12 +1127,12 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
 
         elseif st == :contour
             GR.setspace(clims[1], clims[2], 0, 90)
-            h = colorbar_levels(series, clims)
             GR.setlinetype(gr_linetype[get_linestyle(series)])
             GR.setlinewidth(max(0, get_linewidth(series) / (sum(gr_plot_size) * 0.001)))
             is_lc_black = let black=plot_color(:black)
                 plot_color(series[:linecolor]) in (black,[black])
             end
+            h = gr_contour_levels(series, clims)
             if series[:fillrange] != nothing
                 if series[:fillcolor] != series[:linecolor] && !is_lc_black
                     @warn("GR: filled contour only supported with black contour lines")
@@ -1228,7 +1302,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
     end
 
     # draw the colorbar
-    hascolorbar(sp) && gr_colorbar(sp, clims, clevels)
+    hascolorbar(sp) && gr_draw_colorbar(cbar, sp, clims)
 
     # add the legend
     if sp[:legend] != :none
diff --git a/src/backends/plotly.jl b/src/backends/plotly.jl
index 8d7a0f12..dc06ed45 100644
--- a/src/backends/plotly.jl
+++ b/src/backends/plotly.jl
@@ -354,7 +354,7 @@ end
 function plotly_colorscale(grad::ColorGradient, α)
     [[grad.values[i], rgba_string(plot_color(grad.colors[i], α))] for i in 1:length(grad.colors)]
 end
-plotly_colorscale(c, α) = plotly_colorscale(cgrad(alpha=α), α)
+plotly_colorscale(c::Colorant,α) = plotly_colorscale(_as_gradient(c),α)
 function plotly_colorscale(c::AbstractVector{<:RGBA}, α)
     if length(c) == 1
         return [[0.0, rgba_string(plot_color(c[1], α))], [1.0, rgba_string(plot_color(c[1], α))]]
@@ -506,13 +506,13 @@ function plotly_series(plt::Plot, series::Series)
         plotattributes_out[:showscale] = hascolorbar(sp)
 
     elseif st == :contour
+        filled = isfilledcontour(series)
         plotattributes_out[:type] = "contour"
         plotattributes_out[:x], plotattributes_out[:y], plotattributes_out[:z] = x, y, z
-        # plotattributes_out[:showscale] = series[:colorbar] != :none
-        plotattributes_out[:ncontours] = series[:levels]
-        plotattributes_out[:contours] = KW(:coloring => series[:fillrange] != nothing ? "fill" : "lines", :showlabels => series[:contour_labels] == true)
+        plotattributes_out[:ncontours] = series[:levels] + 2
+        plotattributes_out[:contours] = KW(:coloring => filled ? "fill" : "lines", :showlabels => series[:contour_labels] == true)
         plotattributes_out[:colorscale] = plotly_colorscale(series[:linecolor], series[:linealpha])
-        plotattributes_out[:showscale] = hascolorbar(sp)
+        plotattributes_out[:showscale] = hascolorbar(sp) && hascolorbar(series)
 
     elseif st in (:surface, :wireframe)
         plotattributes_out[:type] = "surface"
diff --git a/src/backends/pyplot.jl b/src/backends/pyplot.jl
index 1e3ca98d..d3e0e091 100644
--- a/src/backends/pyplot.jl
+++ b/src/backends/pyplot.jl
@@ -73,7 +73,7 @@ function py_colormap(grad::ColorGradient)
     cm."set_bad"(color=(0,0,0,0.0), alpha=0.0)
     cm
 end
-py_colormap(c) = py_colormap(cgrad())
+py_colormap(c::Colorant) = py_colormap(_as_gradient(c))
 
 
 function py_shading(c, z)
@@ -1013,6 +1013,7 @@ function _before_layout_calcs(plt::Plot{PyPlotBackend})
                 cmap."set_array"([])
                 handle = cmap
             end
+            kw[:spacing] = "proportional"
 
             # create and store the colorbar object (handle) and the axis that it is drawn on.
             # note: the colorbar axis is positioned independently from the subplot axis
diff --git a/src/utils.jl b/src/utils.jl
index 687b0e49..bea33a07 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -273,6 +273,9 @@ _cycle(v, indices::AVec{Int})       = fill(v, length(indices))
 _cycle(grad::ColorGradient, idx::Int) = _cycle(grad.colors, idx)
 _cycle(grad::ColorGradient, indices::AVec{Int}) = _cycle(grad.colors, indices)
 
+_as_gradient(grad::ColorGradient) = grad
+_as_gradient(c::Colorant) = ColorGradient([c,c])
+
 makevec(v::AVec) = v
 makevec(v::T) where {T} = T[v]
 
@@ -581,49 +584,48 @@ end
 
 _update_clims(zmin, zmax, emin, emax) = min(zmin, emin), max(zmax, emax)
 
-function hascolorbar(series::Series)
-    st = series[:seriestype]
-    hascbar = st == :heatmap
-    if st == :contour
-        hascbar = (isscalar(series[:levels]) ? (series[:levels] > 1) : (length(series[:levels]) > 1)) && (length(unique(Array(series[:z]))) > 1)
-    end
-    if series[:marker_z] != nothing || series[:line_z] != nothing || series[:fill_z] != nothing
-        hascbar = true
-    end
-    # no colorbar if we are creating a surface LightSource
-    if xor(st == :surface, series[:fill_z] != nothing)
-        hascbar = true
-    end
-    return hascbar
-end
+@enum ColorbarStyle cbar_gradient cbar_fill cbar_lines
 
-function hascolorbar(sp::Subplot)
-    cbar = sp[:colorbar]
-    hascbar = false
-    if cbar != :none
-        for series in series_list(sp)
-            if hascolorbar(series)
-                hascbar = true
-            end
-        end
+function colorbar_style(series::Series)
+    colorbar_entry = series[:colorbar_entry]
+    if !(colorbar_entry isa Bool)
+        @warn "Non-boolean colorbar_entry ignored."
+        colorbar_entry = true
     end
-    hascbar
-end
-
-function colorbar_levels(series::Series, clims)
-    if series[:seriestype] == :contour
-        zmin, zmax = clims
-        levels = series[:levels]
-        levels isa AbstractArray ?
-            levels :
-            levels > 1 ?
-                range(zmin, stop=zmax, length=levels) : 
-                [(zmin + zmax) / 2]
-    else # including heatmap, surface
+    
+    if !colorbar_entry
+        nothing
+    elseif isfilledcontour(series) 
+        cbar_fill
+    elseif iscontour(series)
+        cbar_lines
+    elseif series[:seriestype] ∈ (:heatmap,:surface) || 
+            any(series[z] !== nothing for z ∈ [:marker_z,:line_z,:fill_z]) 
+        cbar_gradient
+    else
         nothing
     end
 end
 
+hascolorbar(series::Series) = colorbar_style(series) !== nothing
+hascolorbar(sp::Subplot) = sp[:colorbar] != :none && any(hascolorbar(s) for s in series_list(sp))
+
+iscontour(series::Series) = series[:seriestype] == :contour
+isfilledcontour(series::Series) = iscontour(series) && series[:fillrange] !== nothing
+
+function contour_levels(series::Series, clims)
+    iscontour(series) || error("Not a contour series")
+    zmin, zmax = clims
+    levels = series[:levels]
+    if levels isa Integer
+        levels = range(zmin, stop=zmax, length=levels+2)
+        if !isfilledcontour(series)
+            levels = levels[2:end-1]
+        end
+    end
+    levels
+end
+
   
 
 for comp in (:line, :fill, :marker)