Windows 3.x was white, it is Windows 95 that was gray. Amusingly Win10 was the first time since 3.1 where using the color returned for GetSysColor(COLOR_WINDOW

Windows 3.x was white, it is Windows 95 that was gray. Amusingly Win10 was the first time since 3.1 where using the color returned for GetSysColor(COLOR_WINDOW) would give you a "correct" color for the window background :-P.