Most people color when they stabilize by adding dyes to the stabilizing resins. Multiple colors are done by stabilizing multiple times, curing the resin between each step, and bringing it to a higher vacuum level each time than the last, so the resins penetrate more.
So for example, you might take your blanks and put them in your chamber with stabilizing solution and blue dye, then draw a little bit of vacuum (or none if the blanks are very soft) and let the colored stabilizing solution work in for a while. Remove the blanks, let them drip drain, and cook them to cure the resin. The blue dye is not "Fixed" in the blank, in the softest areas of the wood. This blue resin, since it is cured, will not dissolve in the next step...
Take your partial blue blanks and put them back in your chamber with stabilizing solution and red dye, then pull a full vacuum (or just higher than last time, but less than full if you are planning on more colors...) and let the resin work in for a while. Remove/drain/cook again to cure the red stabilization.
Repeat with another color if you didn't go full vacuum the second time.
When you're done, turn that sucker and post photos to show it off...
