Pur Filter flashed all colors?!?!?

So I have the Pur Water Filtration System, MineralClear, 1 system and I installed it in my dorm bathroom, but I take it off just so no one takes it. I installed it about 2 months ago and I used it for like 3 weeks and then I began working and I haven't used it because I either had bottled water or I stayed at home. Point is I just used it for a while then I just left it in my dorm. Now it's been like almost 3 months and I just used it and all the colors for the filter status came up Green, Yellow, and Red. So i figured maybe its dirty, so I took it apart and I saw that the filter had VERY little gooey stuff but VERY little so I washed it off and everything else as well. I let the water run, then tried it again and the filter status color was Green. So I am unsure what to think. Should I still change it?