Fan Casting Real Is Brown in Sort by Tropes

Desaturating or heavily tinting a game a single color for the sake of realism, usually to a sepia effect (hence the trope name), but sometimes blue or pure grey. Giving a game a narrow color palette can make it look gritty, dramatic and "realistic" and stand out from similar titles. Done well enough, a game and its color scheme will always be associated with each other. In practice, this means a world of brown, grey, and the occasional red (y'know, from the blood splatter on the camera).