Is it mold - the diagram
Can a pellicile stick to the bottom of a bottle? I got something white and snotty at the bottom of my mead once. It was in a bottle that wasn't sterilised just rinsed with washing up liquid and forgot about for a year.
There is no way it was yeast sediment.
Maybe pectin?
I've never had it, the closest thing I can think of is a vinegar mother, but you'd definitely notice that.
Oh yep just googled vinegar mother. It looks exactly the same to what I had.
I thought the mead tasting similar to vinegar was just me having no other refence rather than it litterally being vinegar.
You can go from "on top" straight to the colors