White and yellow are dive balls. Yellow was commercial diving but all the white balls with the exception of the old WillyT and Kodiak Queen have been replaced with yellow. Orange balls are day use for snorkeling. All the above balls are supposed to have a 90 minute limit. Avoid using the yellow balls from 10 to noon and you won’t interfere with the commercial guys.
In the anchorages you will find white balls for overnight as well as the red boaty balls that require a reservation. White balls are FCFS.
The only place boats overnighting on dive balls seems to be an issue is the old WillyT in Key Bay. You will occasionally find boats overnighting on orange snorkel balls but not a huge issue. A bigger issue is boats camping on the orange balls eating lunch or sun bathing with boats waiting.