Green tint on screen

My tablet works fine except that everything has a green tint to it and all pics look weird. I tried factory reset, but green tint is still there. I'm very careful with my tablet. It's always had an Otterbox, rarely dropped, so there's no cracks or scratches on it. It is about 3.5 yrs old. Wondering if maybe the LCD needs to be replaced. Any help would be appreciated.