It’s hard to fine-tune colors with the tiny color wheel. I suggest a larger color wheel, a pop-out button, or an automatic pop-out of the wheel upon hover.
My current workaround is to turn my mouse sensitivity wayyyyy down. Sometimes I use the RGB sliders, but that’s tedious.
And am I missing the color-code input? e.g. #ffffff for white. because then one could use an external color picker, and copy-paste the code into SU.