I am using Aspose.Excel (22.214.171.124) and the background/foreground color of a cell cannot be set. I have also tried the evaluation version of 126.96.36.199 and it didn't work either.
Here is the code:
this.Worksheets.Cells[10,0].Style.BackgroundColor = Color.Yellow;
Before I set the background color, the colors have already been added to the palette.