Sure, but I don't know if you really want to know "why"?

The light on the scanner has a slight pinkish tint. The scanner color corrects for white balance, so it turns things that are pinkish, into white.

Thus, everything in that range of the spectrum is converted to white, so everything else doesn't have a pink tint. (same for yellow and why old printing cameras wouldn't see blue, so it was used for editing gallys and on photos. Some ortho films, don't see red, that's why you can use a red light in a darkroom and not ruin the photographs... the list goes on)

That's my theory and I'm sticking to it.

Alternate answer. The scanner receptor can't see that color, so it's just turning it white.

Same basic idea in either case.

It's white because the scanner sees it as white, or can't see it as anything, so it's not there, and it's white.