Disambiguating overlapping colorscheme names

[asinghvi17]

There's some discussion going on in PlotUtils about switching to ColorSchemes as a provider of color gradients. However, there are some overlaps in PlotUtils' gradient names; for example,:rainbow exists in misc and colorcet.

It would be nice to have a way we all agree on to handle that; either by manually ensuring that there are no namespace conflicts, or some other system.

(Also, quick question - is the library threadsafe? It looks like all the colorschemes are stored in a global Dict, which may lead to some issues. I'll test it in a bit.)

[cormullion]

Threadsafe? I don't know, sorry, and will watch your analysis with interest if not understanding ... :)

As for the namespace issue, I'd guess that more people have used PlotUtils than ColorSchemes, so perhaps the ones in PlotUtils should take precedence. (Although the PlotUtils:rainbow scheme is just a renamed ColorSchemes.rainbow_bgyr_35_85_c73_n256` I think.)

I'm in favour of keeping ColorSchemes simple, rather than getting complicated like PlotUtils... :)