Place a default block of wood or fencepost and right-click on it with dye
(only the original wood/fence are supported right now, not acacia/jungle/etc yet)
Digging the block gives you back plain wood and the dye you used.
To make a stair/slab/etc colorized, add wood to the circular saw, cut, place the stair/slab/etc, right click it with dye.
Digging the stair/slab/etc gives back the default wood version, and dye.
Vanessa Ezekowitz