Maturing or something else

#1
I've had Spike now going on about 9 weeks and I came home today to notice some discoloration around his face. It's below his eyes and around the mouth area. I was gone from Wednesday afternoon to today around 3pm.

You can see it in this pic:



After looking at that pic it seems it goes to his side fins some too. It's the "gold" in the pic, he didn't have that before.

This pic here was taken on Sept. 23rd.:



Is this something I should be worrying about? He's acting fine, ate all his food after I fed him this afternoon and is swimming around dodging the flashlight I was using to try and better see the new hue he's got. Plus the new tone seems to shimmer metallic like the turquoise he has so I want to think it's nothing bad and that as they age they get some more "beauty spots". :)

I just took my water parameters and the Ammonia is finally at 0 *BOUNCINGS *celebrate *thumbsups and my Nitrites are finally going back down and are at .05 from 1 or more last week.

I'll try and get another pic this evening when he flares up when the lights are off.