Even looking at their site, the mail icon drives me nuts. Personally, I don't like the cyan-to-blue because it looks odd that the gradient shifts so dramaticall

Even looking at their site, the mail icon drives me nuts. Personally, I don't like the cyan-to-blue because it looks odd that the gradient shifts so dramatically in hue. The Twitter icon, on the other hand, is fine because it's not really a shift in hue but in lightness.