Wayne, I don't know what you've done in the past that would result in a mottled color. I have not had that problem, except on the outer surface of the rind - and maybe that's what you are referring to. The only difference I see in what you are doing and what I have done is that I add the anatto after the ripening stage and immediately before addition of rennet.
Also, I was stunned by your pressing regime. With your size mold, to achieve 8 psi would require over 400 lbs of weight. I may be wrong, but that sounds a bit excessive. I'm only using 4 psi on the final press, with good results. Of course I don't have a pnuematic press. A stack of 9 concrete blocks might be a bit hazardous for me.