Sorry but I completely disagree.<p>This makes as much sense as designing without different font sizes, designing without borders, or designing without rounded corners so everything is rectangular.<p>Visual design has a vocabulary where everything can be a useful tool for differentiation, but which requires a visual balance between too much uniformity and too much variety.<p>Arbitrarily removing color as a tool and treating it as an "extra" to be added back in later makes as much sense as writing a program that organizes code and variables into separate files instead of separate classes, and then adds back classes later.<p>Certainly, sites should still be completely usable by the colorblind, but color is in no way an "extra". It is functional, and treating it merely as ornament instead will lead to a more limited, more likely worse design -- the same as if you limited yourself to a single font size and were unable to draw extra attention to headings over body text, for instance.<p>And if you want to focus solely on layout? That's what wireframing is for, and you ignore <i>everything</i> else, not just color.