The game's more or less feature-complete, but it only ever has Orange, Green and Blue, and no other colours than that.
Whenever I go back to play the original, I would always ignore the "Harder" levels with more colours, and instead stick to the plain 3 colour mode. It is, after all, more satisfying when you get a nice big cluster at once, and that just wasn't happening with 4 or more colours.
So, I did away with those, but do be sure to whinge if you'd prefer Purple to be added in somewhere, since .. I drew it, so it's doable!!
I don't *think* I missed out anything else important, but do let me know if it's broken anywhere!