if (this.program.segment !== Segment.Y || this.program.segment !== Segment.C) return text

There are 5 different segments and I want to check for 2 specifically, C and Y. If the segment is one of the other 3, I want to return the text. Otherwise, execute what comes after this statement.

Why is this simple OR check giving an error: This condition will always return 'true' since the types 'Segment.Y' and 'Segment.C' have no overlap. I looked at other examples on SO but I don't see how it would work here.