Code review comment for lp://qastaging/~fboucault/unity-2d/new_dash_layout

This merge request leaves the dash with several issues that will need to be dealt with later on:
- background color is wrong (should be black with 69% alpha)
- border color around home items is wrong (should be black with 59% alpha)
- background color behind home items is wrong (should be black with 73% alpha)
- home page's open/close shortcuts buttons: hover and pressed states are wrong
- button for switching to fullscreen mode: hover and pressed states are wrong
- Dash view should use "Preferred Applications" icons where appropriate https://bugs.launchpad.net/unity-2d/+bug/708479