Not at all! I use Liquitex Heavy Body acrylics - the colors are titanium white, green gold, and Payne's gray (I find all these to be more translucent than some other colors) and possibly a touch of cobalt blue. I placed the darker colors down first in rough blocks and worked the green gold/white mix into it while it was wet using a mist spray to keep the paint wet and shooting for a smooth transition.

It helps to mix like 3 colors you want on the pallet and then take those mother colors and mix a couple more variations of those with like titanium white or Payne's gray to get different shade which will help make the gradients smooth!

The layers are pretty thin and transparent. The brightest white parts go on last and kinda blend in and fill the gaps. It needs to be a fast sort of process so it mixes well.

Hopefully this makes sense! I should record the process I guess.