• Inconsistency
• Unnecessary complexity
I don't have much of a problem with the colours. The icons are only half the problem though. Both the text and icons do not stand out enough against the background, and the text and icons seem too close together. The homescreen just looks half finished.
You have a wildly varying base palette, a wild variety of light sources (that's what a gradient indicates, remember!), and a wild variety in complexity (contrast "phone" with "settings").
The net result is an icon package that feels haphazardly thrown-together by multiple teams of wildly variant skill levels who didn't communicate at all.
Even if all the icons looked like Passbook or Safari, it'd be better than the current setup, because it would at least be consistent.
Shocking, right? Things looks half finished in a pre-release beta. What were they thinking?