Place 1 tbsp. of a fiber reactive procion dye and 1/2 cup of plain salt per gallon of water you add into a 5-gallon dye bucket. Three gallons of water (with dye) will give you room to dye about 2 lbs. of wood chips. Mix it thoroughly. Water-based dyes will work, but can bleed and fade. A fiber reactive dye will require a soda ash fixative to prevent the wood chips from fading quickly.
Dissolve 1/3 cup of soda ash in hot water for each gallon of water you added to the bucket. Pour the soda ash solution into the dye bucket.
Place the wood chips in your dyebath and leave them for up to 2 hours or until they turn the color you want.
Rinse the chips under cold running water.
Spread out the dyed chips on a towel or tarp to dry.