Revert "Make header sprites theme-agnostic (b&w with transparency)"

This reverts commit 380e9f89aeed70144a3f1d9f3526eb4c88692fad.

Change-Id: Ic8c5fb005905622dd264463c8127ee74340c5579
Merge "Revert "Make header sprites theme-agnostic (b&w with transparency)""