Try using a solvent such as propylene glycon (antifreeze) or a mild acid (acetic--vinegar) to increase penetration. The pg will also reduce possibility of rot if the epoxy gets scratched through and water gets to the wood. I did this experiment on black and white photo paper as part of a 4-H photography project over 25 years ago. I found that most solvents other than water carried the Rit Dye and food coloring I was using deeper into the surfaces being colored.

To me, commercial wood dyes would be "best" (in terms of consistency and getting it right the first time), if they don't affect the epoxy, but playing with other ideas sure is fun.

Wynne

> If someone wants to try these combinations and post results, it'd be
> worthwhile. Try it with and without changing the blocks into fresh dye,
> and go for as much as a month of soaking (let them waterlog). Blue and
> Purple are good rich colors to use. Green turned to black with extended
> soaking, but not so with most other colors. Surprisingly, yellow got rich
> in color quickly (it was a golden yellow).