Bug summary

mcolors.to_rgba_array("none") returns an empty array whilemcolors.to_rgba("none") andmcolors.to_rgba_array(["none"]) return (0,0,0,0) (which is the documented value of None) and this leads to inconsistencies when trying to usemcolors.same_color

Actual outcome

>>>import matplotlib.colorsas mcolors>>> mcolors.to_rgba("none")(0.0, 0.0, 0.0, 0.0)>>> mcolors.to_rgba_array("none") array([], shape=(0, 4), dtype=float64)>>> mcolors.to_rgba_array(["none"])array([[0., 0., 0., 0.]])>>> mcolors.same_color("none", mcolors.to_rgba("none"))False>>> mcolors.same_color(["none"], mcolors.to_rgba("none")) True

Expected outcome

>>>import matplotlib.colorsas mcolors>>> mcolors.to_rgba("none")(0.0, 0.0, 0.0, 0.0)>>> mcolors.to_rgba_array("none") array([[0., 0., 0., 0.]])>>> mcolors.to_rgba_array(["none"])array([[0., 0., 0., 0.]])>>> mcolors.same_color("none", mcolors.to_rgba("none"))True>>> mcolors.same_color(["none"], mcolors.to_rgba("none")) True

Additional information

I tried the quick fixes of changing the return here toarray([[0., 0., 0., 0.]]) andnp.array([to_rgba('none')], float)

That yielded a ton of test failures, mostly around colorbars/contours, hatches, and but roughly the diffs all looked something like this:

contourf_extend_patches (actual, expected)

colorbar_two_slope

Also I realize this could be not worth fixing and a quick fix is to castnone to a list insame_color