Module for generating nice colors/color schemes

[byorgey]

I often find myself at a loss as to how to pick some nice colors for my diagrams. I end up just using the color names I know (red, blue, green, ...) but this means I often run out of colors, and those colors are not necessarily the nicest for whatever it is I want to do.

Someone who knows a thing or two about design, color theory, etc. as well as how to use the colour library (or just someone willing to learn the foregoing!) should create a module with some functions for generating colors/color schemes. Ideas include:

• Use evenly spaced points along a space-filling 3D curve through some color space to pick a sequence of distinct colors where adjacent colors in the sequence are "similar" (e.g. see http://corte.si/posts/code/hilbert/portrait/index.html)
• Or do something similar for picking colors spaced around a color wheel
• Generate "opposite" pairs of colors or contrasting triplets of colors, etc. (maybe this is just the same as the above)?
• Provide an easy way to load color schemes from some publicly accessible repository (e.g. https://kuler.adobe.com/)
• Generate a sequence of colors "interpolating" between two given colors by traveling around a color wheel or through a color space. (I am not sure exactly what doing blend k for values of k between 0 and 1 corresponds to, but it seems like it sometimes doesn't look like what I expect.)

I'm sure there are other cool things that could be provided as well, these are just suggestions.

[byorgey]

This might be helpful: http://hackage.haskell.org/package/adobe%2Dswatch%2Dexchange

[byorgey]

Another idea (from ClaudiusMaximus) is to pick successive points in a color wheel by rotating by the golden angle each time.

[cartazio]

I've some thoughts on this i'll start experimenting with / borrowing from d3 and other communities later this month. Happy to try and make it diagrams generic rather than specific to my use cases

[byorgey]

More potentially relevant links:

• http://colorschemedesigner.com/
• https://github.com/mbostock/d3/wiki/Ordinal-Scales (scroll all the way to the bottom)

[jeffreyrosenbluth]

I issued a pull request for a module palettes that can serve as a start: #139.
All it does right now is provide a small API to use the colors from d3's color categories.

[bergey]

@jeffreyrosenbluth has uploaded palette to Hackage. I think it fulfills most of the goals of this Issue.