When I create characters, I assign a colour to them as a shorthand for personality on a superficial level. I use it as a starting point. This tends to influence initial sketches of their clothing but I later branch out to using different colours. However, I'll still keep an item of their assigned colour on their design such as a red hair tye.
However, I don't have synesthesia or anything like that. I just like to use colour theory as a way to get started.
_________________
Support human artists! Do not let the craft die.
Almost 25. Near the spectrum but not on it.