What kind of stabilizing resin are you going to use? If you are using a heat cured methacrylate ester, then I have found that Alumilite dyes work the best. I have tested a number of different dyes including transtint mentioned above and the Alumilite dyes provide the best results. They are very concentrated and they are reactive dyes so they will polymerize with the resin and not affect the chemistry. I have had transtint cause the resin to cure with a rubbery consistency.
If you are using Minwax Wood Hardener or any other concoction that requires the resin to "dry", then transtint will work well. However, Alumilite dyes will also work and they are considerably less expensive. A 2 oz bottle of Transtint runs around $16 where Alumilte dyes can be purchased direct from Alumilite for $5 per 1 oz or $10 for the same quantity of Transtint.