It's like Miku v3 vs Miku v3 VIVID or Miku v3 DARK, these (in V3 terms) are (As Sunny mentioned) called Appends, but in utau terms these are usually referred to as expressions, and because OpenUtau exists, we're kind of seeing a shift into them called "colors".
Both are used interchangeably, at least with my banks!
I.E. A Multiexpressive bank with a standard tone, a power tone, a soft tone, etc.. would be the same as a bank with Colors labeled Standard, Power, Soft, etc..