Hi! I couldn't be sure without knowing more; pictures might help, but the default body parts provided by LL are fully modifiable, so they can be changed in many ways, including tone. If you have a way to reproduce this, that would be super. Otherwise, under good conditions, your appearance shouldn't change unwantedly like that!
I didn't know whether to send a second Bug Report or what, so:
- Right-click in the inventory and create a new Skin.
- Double-click on the new skin to wear it.
- Right-click in the inventory and create new Hair.
- Double-click on the new hear to wear it.
- Edit Appearance and turn ALL FACIAL HAIR OFF (move all sliders to the far left).
Results: See thescreenshot below. Tons of facial hair and the skin of the entire head takes on the color of the hair rather than the color of the rest of the body.
(Click to enlarge; click again for full size depending on your screen resolution.)

I just played some more with the settings. It turns out that if you turn Eyebrow Density all the way down this creepy facial hair goes away and the skin color returns to normal--but then you have no eyebrows, of course. The Eyebrow Size setting has no effect on it whatsoever. Here is a second snapshot with a light hair color, which helps to accentuate the problem:
(Click to enlarge; click again for full size depending on your screen resolution.)

