Howdy! Thank you for the suggestion for the new category–you get to have the first post in it! 
As for Richness and Weight, they do factor into the randomization, but aren’t labeled/indicated in the final pattern. 
So in addition to the attempt to forcibly randomize the colors, the generator also tries to disperse the Richness and Weight of yarns.
I’ve been making some doodles for features like showing the list of colors with a generated pattern and/or a way to toggle on/off an overlay of the Richness and Weight values, but unfortunately, right now those two values are basically hidden.