It really comes down to what color you paint the rest of the room. Ideally you want very dark flat paint on all surfaces including the ceiling with a white screen. This is the least costly scenario and yields the best possible picture. If this is not possible screen color/type becomes a very complex calculation between projector specs and reflective surfaces/ambient light/viewing distances and angles in the room.
"Smart enough to know better, to old to care" ------ Dedicated Bat Cave Home Theater, JVC RS49U/Mitsubishi HC7900DW Projector, 110" 16:9 Jamestown screen with variable power masking for CIW 2.50:1 to 16:9, Marantz 7009 with 7.1.4 Atmos with Ohm mains,3 DIY Subs (2 15" (1 ported, 1 sealed and a 12" 4th order bandpass), 1 DIY butt kicker, Custom Built HTPC, 18TB DroboFS NAS