odd harry mushroom

[DOO-E]

Hey all
I have a harry mushroom. It has turned a brownish green but when it fold up and unfods it is the flouresent green it used to be. But within 10 minutes it is back to its dull brownish green. Although when i turn on my actinics it goes back to flouresent green like it used to be also. Do you have any idea what is wrong with it. Shift what ere you feedin it before you sold it to me?