diff --git a/REQUIRE b/REQUIRE
index 14bcddc8..26866772 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,8 +1,8 @@
 julia 0.5
 
 RecipesBase
-PlotUtils
-PlotThemes
+PlotUtils 0.4
+PlotThemes 0.1.2
 Reexport
 FixedSizeArrays
 Measures
diff --git a/src/backends/plotly.jl b/src/backends/plotly.jl
index 1626d5e2..814e4775 100644
--- a/src/backends/plotly.jl
+++ b/src/backends/plotly.jl
@@ -413,9 +413,6 @@ plotly_surface_data(series::Series, a::Surface) = plotly_surface_data(series, a.
 as_gradient(grad::ColorGradient, α) = grad
 as_gradient(grad, α) = cgrad(alpha = α)
 
-# allows passing a ColorGradient where a single color is expected - the other backends allow this
-PlotUtils.rgba_string(cg::ColorGradient) = rgba_string(cg[1])
-
 # get a dictionary representing the series params (d is the Plots-dict, d_out is the Plotly-dict)
 function plotly_series(plt::Plot, series::Series)
     st = series[:seriestype]