The generalization is that any color other than white, green, or gray may be assumed to be hot. Of course, since cable assemblies are usually manufactured with white conductors, there are rules on how to use them as hot when necessary.
Some of us old fogies can remember when it was a code requirement to color code the phase conductors as well as the grounded and grounding conductors. Sigh...those were the good old days.
Ungrounded and high leg connections are required to be marked.All others are not required to be marked.Would make it easier for service but oh well :roll: