SFGate

rinqreation My guess it's more a matter of taste, I'm no designer so I let my gut feeling do the job. White trims look crisp and spacious (white framed rooms) and are easy straight lines to divide two surfaces. Choose what you like, not what somebody told you to do. Just look for pictures you like and go from there. If you think black backboards will look great with your floor and walls, do it. For example: I have a small bedroom with white walls and dark grey mixed with black carpet, I painted the backboards black, so the floor looks bigger (it really does). Good luck!

aichoucha Hi, thanks for ur response. My walls are going to be white, my doors grey and my floor beige. U ll see it on the pictures.

rinqreation What color have you picked for the windows and doorframes?

ASVInteriors I learned (in Europe) that baseboard colours serve either to visually "enlarge" the floor space; so baseboard usually matches the floor to create the optical illusion of extra visual space. However, I have also seen it used like a mascara: to define a distinct line or create a feature of it.

aichoucha I picked white windows and grey frames for doors