Weird spot on my guppy

[CalypsosFish]

Hello all.
My guppy seems to have developed a random blue spot. It appears to be internal rather than external. Not sure if I should be worried.
He's swimming around perfectly fine and is still eating and seems happy enough.
I did recently treat the tank for ich, maybe he's just consumed some by picking at the substrate ?
Sorry for the bad quality picture

 

[Toad]

From what I can tell it looks like a regular marking, some times when male guppies are younger when you buy them they still haven't developed their full markings.

 

[CalypsosFish]

From what I can tell it looks like a regular marking, some times when male guppies are younger when you buy them they still haven't developed their full markings.

Thanks for the reply!
It seems to be completely gone now. Must have been something he ate.