For a series chart, for example, you will never show more than, say five values, but if the dataset has more than a certain number, no unique colors are provided, no matter how many you have selected to chart. No one wants 100 unique colors to be displayed at one time, but when you have hundreds of unique values and you cannot depict the smaller number you have selected with individual colors, that is unfortunate.
What would be handy would be if colors were applied after the selection is made, so that the renderer only needs to provide colors for a small number of unique values at a time.
We have large datasets that represent data from multiple sites and cannot get unique values to show, even for sites that have a small number of values. It would helpful if dashboards could just pick a certain number of colors and randomly apply them even when there is a large number of unique values.