Experimental Colormaps

[stephen322]

So far I've been focusing on cyclical colormaps (for reasons), but for Velocity Rainbow (and future Rainbow Color?) some non-cyclical colormaps may be fine.

I'm not sure which or how many should be included, but I've thrown in a whole bunch with this pull request. (The dim-to-bright Linear-Perceptual type may be okay for Velocity Rainbow, but should we clip out the black/near-zero colors? Remove these entirely?)

Here's the resources I've been scouring:

I put this as reference in colormaps.py comments:

• matplotlib: https://matplotlib.org/stable/gallery/color/colormap_reference.html
• cmasher: https://cmasher.readthedocs.io/user/introduction.html
• colorcet: https://colorcet.com
• cmocean: https://matplotlib.org/cmocean/
• hsluv and hpluv: https://www.hsluv.org/
• agama: https://github.com/GalacticDynamics-Oxford/Agama/

Some more random sites with collections, previews, and analysis:

• https://github.com/GalacticDynamics-Oxford/Agama/blob/3052049d42fd4df3201dee7b0a2d7edb34412ea3/doc/Colormaps.pdf
• https://nicoguaro.github.io/posts/cyclic_colormaps/
• https://github.com/mahdilamb/colormap
• https://plotly.com/python/builtin-colorscales/
• https://gist.github.com/mikhailov-work/ee72ba4191942acecc03fe6da94fc73f?permalink_comment_id=3708728#gistcomment-3708728
• https://colorcet.holoviz.org/user_guide/index.html
• https://stackoverflow.com/questions/23712207/cyclic-colormap-without-visual-distortions-for-use-in-phase-angle-plots
• https://ifweassume.blogspot.com/2013/05/cubehelix-or-how-i-learned-to-love.html

[stephen322]

Added special colormap "^Multicolor".

[onlaj]

but should we clip out the black/near-zero colors? Remove these entirely?

If someone wants to add a colormap with a black colors, I think it shouldn't mess up the settings; blacks might be there for a specific effect. You can always use different colormap if you don't want dim colors in there.

I haven't delved deeply into this topic, but is it possible to animate them? Something similar to how Rainbow colors work, moving left or right. edit. I can see that changing offset is enough to create an animation

[stephen322]

I was thinking adding Colormap support to Rainbow Color would get the already in-place time-shift for free... But it just dawned on me that Animations could be used as a backlight? I made the Colormap animation just to preview the colors.