Pink and White Roots

[zxyqu]

Hey OB. Just read a question about Blue Roots, and made me wonder about some roots I've seen during my Phal repotting. For whatever reason I have some thick, firm, white roots sometimes with green ends, sometimes not, that are primary at the center of the rootball. And then some others have a pinkish/red tip. I'll be honest I can't seem to find anything on this, as when pink and roots are in the same search I get pink plants with root questions. Hope someone can help. I can try to find one to take a picture of, but they've been repotted, and I dont really want to take all the media out to find the ones I'm talking about.