Ability to apply custom note color to more than one note

I used the picker to set my default note color to a custom color, and I would like to set other, existing notes to the same color. It's very difficult to get a precise match using the picker in those notes, but I don't see another way to do it. Let me know if I'm missing something, otherwise here are a few possible ways to address this, from easiest to hardest:

(simplest) add a 'default note color' control to the individual note color options, or...
(cleanest) automatically add whatever the default note color is to the available set of pre-defined colors, or...
(most flexible) add a control to the picker that allows input of numerical color values, or...
(least likely) allow users to save custom colors to the available set of pre-defined colors

Thank you for your attention to this small detail.