Color Choice "Lock"

I like to use the same color for an entire piping system and fittings. My main water line is dark blue and all the fittings, valves, etc. are the same color. Just makes it easier to see on the page and reports what belongs in what system. Having to choose a color every time I choose a different fitting or valve just slows my process down. It would be much easier if I could choose one color, work the entire system and then change the color when I am done with that system.

So can an option be made to "Lock" my color choice until I change it?