Despite the naming in colorMap, Hubitat seems to use HSV, with another important difference being that the hue parameter is expressed in a range of 0..100 rather than 0..360, presumably for legacy compatibility reasons. More discussion in this thread:
With that in mind, my advice is to ignore the 'level' naming with any relationship to the brightness level in dimmer terms. And use it as the V value in an HSV converter to get RGB colors (or whatever you need).
