Need help finding proper Led driver IC
A current mode boost converter looks likely at least for the 30W part, the 20W part red has an inconveniently low voltage and would really want a buck/boost stage (Do look at the output numbers for those two choices, it is not clear that the 30W part is actually significantly better then the 20W). 

There will be external inductors, and probably fets and I might be very tempted to do one boost converter to say 36V or so, and then do a current mode buck per colour (Less mosfets, and buck regulators are more standard then boost ones).

I would be thinking that both TI &amp; linear tech probably have something workable.