Well I bought a bunch of colors from a fella and have been playing with them. They are from spike it. I usually use the do it x2 colors. What I notice is the colors from spike it tend to make the essential plastic more rubbery or thicker in nature. Anyone else notice and differences.
Colorants should not affect the plastic in the amounts we use unless something is in the colorant itself. I have many of the X2 colors and even some of the old Caney Creek colors yet along with 40 or so MF colors. I use the MF stuff to adjust colors and hardly ever use the MF stuff stand alone except a couple of the changeable color so I can't really say if I've seen anything there. I do have or use spike it stuff at all.