In the scenario below, both visualizations are linked to the same source table. It would be ideal if the colors were set at the source table level so they matched the same variable across visualizations. This should apply to any visualization, so summary change and summary number would not all appear as the same color.
I have a donut chart visualization showing all traffic sources, direct traffic is about 85% so you can't really see the details of the other channels. Below this I have another donut chart visualization showing all non-direct traffic sources, so you can see the full breakdown. Because colors are auto-allocated, I have the same color representing direct traffic in one viz and SEM in the other viz. This is not helpful and is quite confusing at a quick glance. If colors could be linked across visualizations, or manually allocated per viz, it would be much more executive dashboard friendly.