Primitives in Urho3D and change color UI

Hi everyone.

I would like paint primitives like sqaures in the UI, but I don’t know how do it :blush:

I read the documentation, but i can’t find functions to draw primitives.

Other question. Is possible change the background color of UI? Is right do it creating a window and set a color?

Somebody can help me? Thank you very much! :wink: