Just placing a DIV with white background and any opacity value:
background-color: rgba(255, 255, 255, .5);
over a white (255x3) background. Actually DIV's background will be 254/254/254. This happen only in Chrome. FF/IE/Opera/Safari is ok.
Bug?
As Möhre said you should have good display to see this.
– Levon Jun 08 '14 at 14:18