Fix wrong background color
Fix wrong background color

imjerrybao/FSImageViewer,yichizhang/FSImageViewer,harlanhaskins/FSImageViewer,tooploox/FSImageViewer,ListFranz/FSImageViewer,arsalananwar/FSImageViewer,shenhzou654321/FSImageViewer,iwakevin/FSImageViewer,x2on/FSImageViewer,Voxer/FSImageViewer