It recolors specific voxels, which are a specific color in a secondary QB.(black by default)
Like so:
The Program only recolors voxels which are black in the secondary(NEG) QB. That way the red tablecloth gets recolored, but the wooden table stays the same 
My old old version of this program(which I lost due to a HDD fail and never released) worked by only replacing certain colors in the original. This newer method is much more flexible. =]