I believe - it’s called Hex Value? (uncertain)
When moving the cursor in the color wheel - passes through too many colors too quickly…
Feature Request:
Double Click on Hex Number - Then Enter your specific code!
If I understand your request correctly, this can already be achieved, and is the only way I do things with colors. Set the Apple Color Picker to the RGB slider option, in there you can enter a HEX value for the color you want.