It's not illuminated, like her mask is.
There's even pink over her face, the kind of pink that surrounds Yoshiro when she's dancing at night.
Is it a hint at relationship with the Maiden or a hint at her being merged with a previous Maiden?
The other visible flesh on her is colored this yellow/blue combo. It's only her face and neck that has pink.
In comparison to the masked version...
There's pink as well, near her neck.