I just find it is fine to just use
line.color:=GetDefaultColor(I) for ith line. The precedure of getdefaultcolor is fine.

Mike

Thanks, Pep. I get to know the colorpallete. using Rainbow pallete, the colors of lines are quite close to each other. Thus, I still use default pallete, and set line.color:=GetDefaultColor(I mod Length(TeeProcs.ColorPalette)), so that color will repeat that in the colorpalette when the number of li...

I have a chart with number of line series up to 25. These series are partitioned into different group.

The problem is that the lines have automaic different colors in the first ~20 series, but they become alway gray colors in the last few line series.