Save custom colors into the color bar, or create a palette

If I made a new color using the custom color wheel to use for sticky notes/arrows/etc, I have to save the Hex of that color and apply it again in the future (or if I switch to the draw tool, etc). It’s a bit frustrating and inefficient that we can’t keep custom colors in the color bar or at least have an ability to save new colors into some sort of palette.