Both the handbook and the official video paint Skaven half-assedly. I of course do no have the talent to paint them to the level of someone who did that for 10-20 years. But those are rats, rats should have pink tails, and both of the official guides don’t care to paint them any differently at all.
Stormcasts are pain to paint mainly because of their shields and pauldrons. Skaven require a lot of colors.
There’s metal.
There’s wood.
There’s leather.
There are their teeth and nails.
There’s the tail and tongue.
They also have two layers of fabric instead of just one.
And I also decided not to paint fur. In the official art, they are mostly fur-less, with exposed skin and just some patches of fur. But I wanted the pinkish tail to be the contrast, so my skaven have short white fur, I guess.