Okay, as I understand it, the sensor devices (distinct from controls like Slider) have a fuzzy range. For example for temperature and pressure there are not good bottom ends (other than 0 degK and 0 mbar), I assume you have to normalize some set temperature and pressure (as yet unknown to me) as 0 in Rockpool, and some higher values as 1000 (also unknown).
For the light sensor, you do at least have a low end: 0 for complete darkness. If you want to normalize the RGB channels, you could do it based on the maximum of the three alone, and leave the minimum out of the equation. The hue and saturation should come out about right, and value (intensity) is subjective anyway if you're not measuring actual lumens.
Just a suggestion.