Strange discolouration on beardies stomach.

[Cupquakez]

Hey everyone! Quick question for you.
My beardie is now approximately 8-12 months and is as healthy as ever. Loves his crickets, his greens, and is very active and loving. He sheds quite a lot, but I'm assuming this is due to him consistently growing? I noticed today that he's shedding in different areas (left side of back, hind legs, tail, portion of his head) so I decided to give him his weekly bath to assist him. Upon removing him from the bath, tho, I noticed a strange discolouration on his stomach that wasn't there as early as a few days ago. It's not strange in texture, it looks more like a tea stain, almost? Covers a good amount of his stomach, as well. (Not sure if I'm able to add pictures via a cell phone, so that's the best way to describe it). I've dealt with yellow fungus in the past, but I'm thrown off by the texture of this "stain". The fungus I've dealt with before was more of a cheesy type texture.
Does anyone know what may be the cause of this? Should I rush a vet visit or give it till the end of the week to see if it's clears up?
My set up is as follows :
40 gallon tank.
100 watt heat lamp (temperature is around 105F)
10.0 UVB.
Slate tile substrate, but have play sand in a hide for him to burrow. Is it possible this could be a sand stain?
Any help would be greatly appreciated.

 

[Cupquakez]

figured out how to post a picture!

 

[AHBD]

I see just a very slight, pale discoloration but it doesn't look to be anything harmful. His belly is so creamy white that it could possibly be from the sand.

 

[Cupquakez]

I see just a very slight, pale discoloration but it doesn't look to be anything harmful. His belly is so creamy white that it could possibly be from the sand.

It is very light. More prominent in different lighting, but it's nothing extremely noticeable. My first thought was "oh no, yellow fungus" based on my past experience, but I'm thinking now maybe it could be a retained shed. I'm just overly worried because of what happened to my previous baby. I always appreciate everyone's opinions on here as they've helped me out many times in the past.

 

[AHBD]

It doesn't look like Y.F. at all, you're probably right about a shed coming on or left over. I was thinking colored sand, but you use play sand so it's much more likely that it's just a light shed.

 

[Cupquakez]

It doesn't look like Y.F. at all, you're probably right about a shed coming on or left over. I was thinking colored sand, but you use play sand so it's much more likely that it's just a light shed.

Thank you so much for your quick responses.
I'm going to keep my eye on it to ensure it doesn't spread or change in texture. My previous beardie showed signs very early on in his life, and the fungus grew extremely slowly. Was also a much different texture than what I'm seeing here, so I'm hoping for the best.