The lustre formula is sheer, but it can be layered for a deeper look. Gaga is a light, cool, blue based pink. Cyndi is a warm, slightly pinked sheer red.
Gaga is a bit darker pink in real life:
Here are my lips with nothing for reference :
Cyndi is definitely my favorite of the two. It can be applied with a lighter hand for a stained look as well. I want to try some gloss over Gaga to tone down the coolness, but it is a nice baby pink color that I was lacking. Overall I am very happy with these colors in the Viva Glam line!