Would you find it hard to read white text on a white background? I do. Black text on a white background, or white text on a black background gives the highest contrast. That makes it the easiest to read. In between the extremes is a continuum of grey text on white. By definition, grey on white is less contrasty than black on white, and it is certainly harder to read. More and more web sites are inexplicably making their content harder to read by using grey text on a white or even grey background. It is beyond me why they would choose to do this. It is an ill-conceived fad among trendy webmasters with young eyes, and I hate it!