I have a samsung tab 3 and i clicked accidentaly while i was going to open a program 'always' instead of 'just once'.. now when i open gallery it has changed ..before it was white now is black and it has a strange way of opening photos that i dont like it.. i have tried two ways..i went to settings and application manager,i tried to do the clear default button but it wasnt avaible at gallery application..ai tried also to reset apps preferences but nothing has changed..can someone help me plz..