/ic/ - Artwork/Critique

I want to learn how to render stuff like this, what I mean is how
>What color do they use
>How do they use masks
>What type of brush do they use
If I painted it with my skills the colors may be right but it will not be clean like that pic, I have some tutorials on exhentai but they are in japanese

I want to learn how to render skin like this, I have some tutorials on exhentai but they are in japanese