Context menu color choice and VisBug don't match

[argyleink]

found by @zeaccs

show visbug -> hide visbug -> change color mode to rgb -> show visbug again

I believe the issue that when hidden, eject.js deletes the node and restore.js creates a new one that never got the attribute update from the extension event. need to find a way to create a node in memory and share it. That way, no new ones get created, it's always the same first VisBug element, but depending on restoration or injection, it's present in the DOM.