How do you color code the variables in a biplot?

I'm trying to color code select variables/loadings in a 3D biplot attained from running a PCA, so that those variables most associated with say component 1 are in one color, component 2 in another, etc. I know how to label them, but trying to use the brush/select data option in the plot menu doesn't seem to work for this type of plot.

Searching for an answer someone posted a similar question, but their solution was to overlay three different plots, each color coded, and that's definitely not the solution to my problem. If it's a matter of an input function I'm unaware of, or if someone has a PCA plotter GUI or function that can help with this, I'd greatly appreciate it!

[dpb]

Why doesn't the three overlaid satisfy? It'd be my first/simplest route.

Alternatively, find the handles of the various objects associated w/ each variable and set() their color properties as desired.

I've never used biplot (and really don't even know what one is) but probably one could wrap the above in a function to hide the complexity if do this frequently.