I'm normally using a light background color in all my Emacs faces. But I'm used to dark backgrounds in a terminal. Therefore I wanted to set the background color of ansi-term to black. However when I do this only the part where text has already been written to is colored correctly, the rest of the background is still light as in other faces. I'm looking for a way to completely set the background color of ansi-term to black. An example: https://i.sstatic.net/F3pra.png
Check color-theme-buffer-local. I think this is what you need.