If you mean castes, then there are only 12 known castes (rust, bronze, gold, lime (which is extinct on Alternia), olive, jade, teal, cobalt, indigo, purple, violet and fuchsia), plus one known mutant caste (candy red).
Now, if you mean actual hex values, then I guess you can go pretty much nuts (as long as it’s not too dark, too pale or too bright). You see, there are hex value differences even between members of the same family (Meenah has the same blood colour as the Condesce, but Feferi’s is a little brighter), and the Grand Highblood’s chamber showed quite a few different-coloured splatters on the walls, so the colours we’ve seen in canon aren’t the absolute only ones. You can see this ask for my method to divide castes, as well as another pretty handy guide to choose blood colours.
So, in short? Your trolls aren’t bad for not having THE EXACT SAME blood colour as their canon caste counterparts. They WOULD be bad, however, if they were obviously mutantbloods (too dark, too pale or too bright) and didn’t hide it, if they had shades instead of colours (black, grey, white…), or if you made an absolute new caste (“dis mah fantrol shes a hot-pinkblood shes higher then feferi xD”).
- Officer Dorkleer