Colorblindness, well more accurately "colordumbness" as my eye doc puts it, prevents me from doing my own dubbing blending. it looks like it would be fun. I have a grinder to do some minor blending like saving the trimmings from zonker strips, but to try to blend colors would end in a horrific disaster.
I have to buy mine and make sure all the packets are clearly marked as to what color it is. When using dispensers I put a 3x5 recipe card inside the lid and write the colors in a grid to match the compartments.