Look for more accessible colors for rating history chart

[TBestLittleHelper]

I got the colors from here : https://github.com/lichess-org/lila/blob/002c73bad9ab011b52d8c43ddec56118e9166076/ui/chart/src/ratingHistory.ts#L50

If you put KotH and Antichess into https://davidmathlogic.com/colorblind/#%23DF5353-%23D55E00 you will see that tritanopia makes them difficult to tell apart.

Obviously we have many variants, so finding non conflicting colors is hard. I put all the colors into the davidmathlogic from earlier. In general it's ok, but seems that the current palate is particularly difficult to use if you have tritanopia. If finding colors that work across the entire population is impossible, maybe it's worth thinking about having color schemes. ( This is what github does : https://github.com/settings/appearance )