I'd actually prefer older Marici have slightly darker skin than the young. Basically, she's lived underground most of her life, and I figured she'd probably get slightly tanner if she'd been outside for some time. I think I might have it, but I'm not quite sure.
Then give the younger one the older one's skin, and give the older one darker skin. The older one's skin tones are perfect for "sickly pale" but the younger one just...doesn't synchronize.