Can fissure sealants become discoloured? i have been using whitening strips and i have a green little blob where mine are. is this difficult to fix?

No. Easy to fix: Sometimes sealants can chip or leak at the edges and stain or decay can get underneath. Your dentist can evaluate this and if you need a replacement it is very easy and it will white and protect your teeth as it was designed to.

This is common.: The resin material in composite fillings or sealants can absorb color from food or anything in your mouth. Sometimes staining is the only thing going on, other times decay will undermine a sealant. Have your dentist take a look for a quick answer about what you should do :).

Sealants: Yes, sealants can become discolored. If seal is broken underlying tooth can become decayed, causing discoloration. Some foods, beverages, or chemicals can cause discoloration. Best to have discolored sealants reevaluated by your Dentist and, if necessary, replaced.