Tube Worm

[Marie7]

I have 2 tuve worm on my tank but the pink and black one which is beautiful is showing something like if its cotton or spelling something that I don't know what it is or whats going on, the other tube worm it’s fine.
Here’s picture of it and a video, can some one tell me what’s going on? It displays its color and hair , i call hair or legs beautifully but then i saw it that gets the same way during the day. Thanks all

 

[Bhor217]

Hard to tell from pictures, could you try sending ones with more of a focus of the subjects in question?