Lawnmower blenny losing color?

Hi everyone, about a week ago I noticed that my blenny has a big white discoloration on his side, which I believe I have not seen before. He is very active and eats fine so I am stumped as to what this may be. I tried looking everywhere and couldnt find anyone reporting anything similar. I was hoping someone might give me an idea of what this might be. Thanks in advance, and I hope he is fine. Included are pictures, first one shows his right side which is normal and second the left side which has the faded out white patch. (Sorry about the quality, was using my iphone as my camera is out of comission for a short while)

 

If he's active and eats fine and your water parameters are ok - I think you should be just fine. If he was acting sick or lethargic id say it was from improper nutrition. They do change color because of mood - if they are stressed they turn white-ish. Do you think this could be the cause? Also - when I turn my lights on in the morning, most of my fish are very light and uncolored - are you seeing this spot first thing in the morning? Or if it there all the time?

 

this mite sound weird but i have seen my lawnmower blenny change colors,he will change from a greenish grey to pure black and white.depends on what rock he is on.JOE