I am using the GoogleMaps-Chart from the example files. Expressions are longitude and latitude.
Setting the Background Color Property of one or both to something static (like =rgb(0,255,0) ) has no effect.
The lines seem to get their color according to the last dimension uesd, as before.
Of course one can change these colors and set them to a fixed value or calculate them by expression, but it seems like this expression is evaluated before the chart is drawn and one color expression yields always the same value during the drawing process of the chart. I tried something like
as expression in the color tab. Where COLORR is a field name with different data for each line. This did not work.