Confused about track delay functionality

[chewywater]

OK.
I've been using live for a while now but just started trying to use track delays yesterday.
I have a few midi tracks I'm attempting to delay by 90ms or so (I do all my work in arrangement view).
Sometimes when I punch in the delay value, the little arrow to the right of the value turns red. Sometimes it doesn't.
Sometimes I zero the delay value but the track continues to play as if it's delayed.


Can someone tell me how these track delays work?
What does it mean when the track delay arrow turns red?


thanks!