Morph is more of a term used to describe traits that are specifically breed for, such as a Citrus that is yellow in color.
What you are seeing is a reaction that all beardies have of lightening ad darkening their skin. WHen they want to get warmer and absorb more light in onrder to do so they wil darken up as the dark colors absorb more light energy. By placing him in warm
bath water he is surrounded by the warmth and is lightening as he does not need to absorb as much light energy for that warmth. This same color generally should be lighter after basking for a bit if temps are high enough. Have you measureed the basking temps and good on UVB setup? If you are unsure post some pics of the setup and temps / UVB used and we can help you make sure everything is setup nice. Its all a bit daunting at first, but we are happy to help.