some of my sheep turned white

so some of my blue sheep turned white. it happened when i logged out. it could be because the sheep were in two chunks at once (i lost all my sheep once due to a chunk issue) the sheep were still there but white and not blue/light blue. I first noticed this issue in 1.16.40 and i do not think it has been fixed. when i logged back in about half of my blue sheep were white. it could of had a problem when saving the data.