The only "absolute" in regards to any given level is that colors16-31 are used for sprites, so those particular colors are set in stone (which in effect also means 48-63 for ehb levels).
If copper gradients are suited to a them I dont mind using them.
Anyway, I'll upload v0.3a (revision no. picked at random, but it "feels" about right
)somewhere a little later today. I had planned to do it yesterday, but I ended up making a few changes which introduced some new bugs as well