Color schemes for particle overlays are troublesom

Currently handling of color schemes for particle overlays assigned to a polymertype are often so close-colored that the color representation becomes useless. The color scheme can be changed pseudo-randomly by setting a different color seed in GE > Display > Set color seed. The default value is default which, in a example scenario of 7 polymer types leads to 4 greens and 2 reds which are almost indistinguishable for a human observer.

Changing to a different value helps, but is is oftentimes very time consuming or not feasible to find a seed that produces a clearly distinct color set

Proposal for better color handling ( to be disccused / improved)

• depending on the number of polymer types a pre-defined color scheme colud be used, eg:
  • n <= 10: take first n entries of a cat-10 scheme
    • example: https://vega.github.io/vega/docs/schemes/#category10
  • same could be implemented for n <= 20
    • example: https://vega.github.io/vega/docs/schemes/#category20
• when more colors are needed than provided by the available categorical color palette, n colours should be sampled at regular intervals from a sequential multi-hue scheme, like:
  • this https://vega.github.io/vega/docs/schemes/#turbo
  • or this https://vega.github.io/vega/docs/schemes/#rainbow