Question

lips have a reddish hue because of their abundant supply of superficial vessels and the reduced amount of within their outer epithelial layer.

Explanation:

The reddish hue of lips is due to blood vessels (vascular) supplying blood which has red - colored hemoglobin. Also, the outer epithelial layer (which is part of the skin) has less melanin (the pigment that gives skin its color) compared to other skin areas.

Answer:

vascular; melanin