I am thinking of getting some Stick Fast resin for stabilizing poor quality woods like spalted beech and buckeye burl. What sort of things can you add to the resin to stain/dye the wood that won't cause a chemical reaction ? Stick Fast do make colorants but expensive and limited colours.
Considering that you will need a vacuum stabilization system(about $325 new) and a quart of stabilizer (about $34) it seems that $10 for a jar of dye is not out of range.
However, to get colours beyond the primary colours offered by Stick Fast you would need to buy three jars (red, yellow blue) and mix any color you want. Relying on basic colour theory (red and blue make purple; blue and yellow make green; etc) you can, with patience, mix any colour you want.