retained shed maybe?

[XCrunner]

for about the last month or two my 11 month old beardie Dino's bottom half of his tail has been darker then the rest.
The cream/tan stripes on his tail stay pretty much the same all the way down, however, the brown stripes are darker on the second half of his tail.
here are two pictures i took of it. It is slightly difficult to see in the picture but if you look close there is definitely a difference.

Also i thought maybe it was a retained shed possibly? I've given Dino baths and also a little spray that is suposed to help it along. None of this has done anything. help?

 

[blackbearded]

you know what Im having the same problem however is the tail (up to his vent) thats lighter then his body his body havnt been in a shed for months I think since sept. his tip of his mouth is starting to shed i'm wondering if i should worry about it? he suppose to be very bright much brighter then now. check the pic.

this pic was taken a few months a go now his body is a little darker when he heated.