Nope. It's because the entire animation is able to reuse a small amount of colors to make the whole image. Gifs start looking bad when the number of unique colors are high. The first Gaga avie is reusing the same shade of greens and light brown colors, so it looks nearly spotless.
Fantastic avies BTW. Some of the best I've seen this year.
I need to find different sites than using Youtube and instead of enhancing my colors make them more unify but your avatars are really good. Your becoming another avatar maker here at ATRL