This is a low-priority bug in my opinion, but I don’t want to lose track of it. Right-clicking on the border color and selecting a variable puts it in the border width position instead of the color position of the border rule.
The control also seems like it’s generating some odd rules, but I haven’t taken the time to figure out exactly what’s happening. For example, I see a border-style rule with a border-bottom-width, then a border-top shorthand rule. None of it seems wrong, aside from the color issue, but I’m not following the logic Pinegrow is trying to use.