FileMaker Charts are still a new feature and are pretty limited.
By "color assign tab" you mean the color drop downs in the inspector or the formatting tool bar?
The only color options I see are a "Color Scheme" setting found when you click the Format Chart Button in the Chart Setup. I don't think you'll be able to match up color selections the way you want here.
I want the colors in the 'COLOR ASSIGN' tab [on the main scree] to match my pie chart colors. I hope that these attachments will show what I am trying to accomplish.
I thought it was something similar to that. It can't be done with the current Charting capabilities built into Filemaker.
Thank you nonetheless.