color filling when I don't ask it to

Hello. I am currently working on a document where I use fill color to help organize 'already checked' information, 'information that needs to be further investigated' etc. However the cells have started coloring on their own. I type information into the cell and when I click enter, it turns pink. I don't want it pink. I have messed around with autocomplete and it doesn't seem to be fixing the problem, however when the problem miraculously goes away for a while, turning autocomplete back on will trigger it again. Turning autocomplete off does not make it go away. Help?!