Color Inspector is slow to update

[andrewkaufman]

The color inspector has been suffering from laggy updates or not updating reliably. It seems to be that whenever there are bucket updates in interactive renders it seems to be blocking updates of the color inspector. It gets worse when viewing an interactive that’s passing into other image nodes.

We think the problem is probably that the colour inspector’s work is getting cancelled before it is finished because new buckets are arriving faster than it can keep up.