There was already a question about the possibility to specify a custom color palette. Unfortunately, this is not possible at this time, but it would be nice.
I would also like to have an easy way to determine the color for a specific value. This makes the result for the end user more intuitive. Take for example a color based on a certain status (On time=Green, Little late=Orange, Much to late=Red).
I know you can try to achieve this in the executed query by forcing an order and existence of all possible values, but that is cumbersome. It also effects the performance.
It should be easier.