What's a variegated color on a beast look like? I saw it on another user's gryphon, but the gryphon also had a custom skin on, so I couldn't see it.

When a beast gets a custom skin, the beast's listed colour changes to the skin's name. So that custom skin must have been called "variegated". There aren't any normal coat patterns called variegated.

You can browse all the normal coats by going to the Help tab, then List of Skins. Hope that helps. :)