When I was a child and learning to play the violin, I associated each of the violin strings with a color.
The E string is either a hot pink or a bright yellow. The A string is blue. The G string is a mysterious, dark violet. My favorite is the D string, it'd be a silky brown.
If you play closer to the fingerboard, the saturation drops and the colors start to granularize. So the G string will turn to a puzzling indigo. The A string a faded steelblue. The E string falls sandy. And the D string becomes a very soft darkgoldenrod.
The instrument matters. Different instrument will dye the strings a different shade. My preferred violin might be on the darker but silky side. But I've never owned such a violin nor was I ever able to paint with one such that I can see the colors with clarity.
After I play the viola recently, however, I never see a different color anymore. Somehow all my viola strings are of a same color, and yet I struggle to name one. Maybe I haven't played long enough? Maybe I've lost the ability to see the colors? I don't know. But it's an interesting retro that they once were colorful.