Blood Ravens fleet, modding?

Hi, I am new in these forums so please pardon me if I am not posting this in the right place.
Is there a way to mod an additional sub faction for the space marines fleet campaign? I would like to add Blood Ravens "with a librarian admiral to predict manouvres and attacks etc" would be pretty cool. Even if its just skin colors.

Or is there a chance that they may be officially added?
thank you for your time.

Would love to, but I can not make new graphical stuff nor edit the UI.

What I could do is textwise rename the Blood angels... but the chapter symbol would not change and the vampires are a lighter shade of red.