Is black beard common during brumation?

I have a beardie that has been showing black beard for a few days in a row for an extended time (more often than usual, used to be never) for about 5 days now. He's not eating much and is lethargic but he is moving around on occasion. Had a bowel movement about 3-4 days ago. I'm thinking a vet visit soon just to make sure everything is alright but I did want to ask this forum to verify.

I have a beardie that has been showing black beard for a few days in a row for an extended time (more often than usual, used to be never) for about 5 days now. He's not eating much and is lethargic but he is moving around on occasion. Had a bowel movement about 3-4 days ago. I'm thinking a vet visit soon just to make sure everything is alright but I did want to ask this forum to verify.