The following is a description of the different states
A bar is enabled if
Alert Level - Out of Combat
setting on the Skins Frames Bars Visibility tabAlert Level - In Combat
setting on the Skins Frames Bars Visibility tab, the bar is enabled but can have an opacity that gives the impression it is disabled.
A bar is disabled if
Alert Level - Out of Combat
setting on the Skins Frames Bars Visibility tab