Limited colors for categories

[phoenixr-codes]

When no color for a category is specified, then a color is determined by the category name's hash. This may result in hard-to-read or similar looking colors. Therefore I suggest using one of these two alternative implementations

• Algorithm that limits the color space to easy-to-read (on both dark and light background) colors and additionally separate the difference between colors (such that there won't be one category with the color blue and another one with a slightly lighter blue).
• Use a predefined color palette (adorable2 already provides them). The problem here that can you cannot hash the categories individually so it's probably required to shuffle the colors based on the first/last hash.

Both implementations should of course have no effect to the preferred method of specifying the colors explicitly.