It's unlikely you will find any bugs in how things get colored so what you are seeing is how it works. Try using Orange and watch what turns on. A Single Color Red model will turn on based on the value of the red channel in any color you drop. When you drop White that means Red=255, Green=255, Blue=255 so it turns on all of them. You can't have no color selected so if you check no boxes it defaults to White.
There may be a way to get it to work closer to what you want but I'd have to play around with the program and it's not in front of me right now. What I would do is experiment with the Single Color Custom option. When you select that string type the color will only set that model if the Hue values are within like 0.01 of each other when you convert the select color and model color both to HSL color space. So maybe try selecting Single Color Custom but set it to a red color. I'm not sure you can select pure red cause I thought I saw the program automatically figures out that's Single Color Red and switches it for you but again not sure without trying. Maybe select Single Color Custom but make it red=254 and see how it works when you drop pure red and pure white on it. Let us know how it goes it may help others.
