There is a model type for single color strings aka non-RGB. I use those for my 64 LED string (16 strings x 4 colors) and my 16 three string mini trees. Works great. To do a chase within a color I have my mega tree defined as 4 models each with 16 strings. Same type of thing with the mini trees. It is just that there is no way to draw the mini trees for the preview without creating 48 single color tree models so I just call them as 16 string single line each with 10 lights per string. That lets me put a line on the preview and get something representative of the trees without having to build a huge number of models. Maybe someday a model type will appear for that, but there are higher priority things to be done with nutcracker in my opinion.