I have noticed for about two weeks that my bearded dragons tail is darker. A lot darker than the rest of her body. I'm wondering if it's normal or not.
Do you have any pictures of the the tail you could post?
Perhaps your dragon is going to shed. Many times pre-shed, the tail can appear darker before it lightens up to shed next
Unless he has injured it somehow or has had retained shed to constrict the skin, it should be fine.
Please post a picture for us so we can be sure how it looks.
That looks like natural darkening rather than a problem. It's common for their tails to darken like that. I don't see any shriveling or wound that would indicate a problem. The right leg does look like it's about to shed though.