That's way cool. You could sort of print in full color that way. I guess the question is whether you would be selecting one of n colors per gcode line segment (probably simplest way to do it, with n being 3 or 4), or if you would lase the same spot multiple times under different resin pools in order to try to mix a custom pigment for each line segment, and how well such mixing might work out. You definitely would not be limited to having whole layers be the same color, but this would probably slow down maximum printing speed and introduce surface waves to deal with potentially. Probably is more difficult to pull off the more separate colors are attempted.

Another approach might be to rig a gantry that follows behind the laser spot and dumps or sprays pigment powder onto the curing resin gel.