gallery: make transparency backgrounds look more attractive.
gallery: make transparency backgrounds look more attractive.

Change-Id: Id9bd1905f7608c54861ff3931e56b94afc5688ba

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core