Update workEDU background color to scHighest

bug: 342246204
Test: manually photos:
beforeDT: https://drive.google.com/file/d/14qJDNK2044KQXLLr3NgKMnxRcGysGcf3/view?usp=sharing
beforeLT: https://drive.google.com/file/d/1qwKBSUjGXtqY8PVep7ZT0FhABx2kFGFt/view?usp=sharing
afterLT: https://drive.google.com/file/d/1-rR-5x-vp0WUTlGV8rJMHiHnhQ07FfXC/view?usp=sharing
afterDT: https://drive.google.com/file/d/1szHqOSudhqEF4_AId9xD77YKTmGJt09n/view?usp=sharing
Flag: NONE Color change
Change-Id: I7d41581c613bd719515fcf491967327c989bf91b