Id be interested to see what others say, but my beardie has had the kink at the tip since I bought her home a at a few weeks old. It looked like she had a bad shed as a baby and it got damaged, but after a year, its still like that and perfectly fine. Her tail is kind of like yours where its a tad bit darker than the body. It can change depending on shed cycle.
Im not an expert but i dont see anything alarming?