This first version uses the colors I mentioned above:
This next version uses colors from my mnemonic system for colors, in somewhat pure versions. I don’t think it looks very good though.
Here are the colors for reference:
0 = #858585
1 = #ffff00
2 = #0066ff
3 = #009900
4 = #000000
5 = #804000
6 = #808080
7 = #ff6633
8 = #660099
9 = #ff0033
I’ll try to create something more balanced.