What can be the cause of discolored eye discharge?

Usually : One of 3 causes; bacterial or viral infection or allergies. Sometimes difficult to distinguish between the 3 causes, but viral conjunctivitis is usually occompainied by cold-like symptoms and allergic may be occompainied by other allergic symptoms like runny nose and sneezing. Bacterial usually has heavy drainage causing eye to be matted shut. If you have a painful red eye, see your doc urgently.