>Nothing really concrete, no. They seem in some way to key on colors
>significant to their owners, but there's no solidly definitive rhyme
>or reason to it in-story - they just kind of happen that way.
>Out-of-story it's a bit of passive, sometimes not-entirely-conscious,
>character design on my part.

Makes sense, thanks.

>If I recall my Doc Smith correctly, the canonical Lenses are
>all multicolored, since they're not really one gem so much as a matrix
>of jillions of tiny ones.

You recall correctly. I always figured they looked like opals.

Happy whatever, Ben.