3 fawns and a brindle so I voted fawn
I remember GreysGalgos comment:
I wonder about this. I know Magic, whose thyroid values plummeted just before she went to the bridge, would support this. Several seniors I've had developed low thyroid, 4 out of 13, and one was gone within 8 months, two lived 2 years and Heart is still going (albiet very slow going) so it's been close to 4 years for her.
I don't believe there is a color connection unless it is by geneology--perhaps related. True thyroid defiency is heriditary.
There is a problem in coats and wellness in some dilution, for instance blues & fawns in Dobes. However, my fawn Dobe had no coat problems and her blue sister didn't either. Genetics I believe. The only Dobes I had with thyroid problems were a black and a red!