Thank you for considering Aspose.
Excel 2007 offers themes and more than the Excel 56 colors. Is there anyway to access the theme attributes of xlsx files?
We only support to load the theme from the Excel 2007 template file. We will look into the feature to access the themes by API.
utilize all of the color options within Aspose.Cells?
You can set more than 56 colors of Excel 2003 color palette when saving the file as Excel 2007 file format using Aspose.Cells. Please see the following sample code to set a color which is not a part of 56 Color Palette of Excel 2003.
Workbook workbook = new Workbook();
Style style = workbook.Styles[workbook.Styles.Add()];
// Color not in Excel 2003 56 Color template
style.ForegroundColor = Color.FromArgb(20, 228, 241, 155);
style.Pattern = BackgroundType.Solid;
Cells cells = workbook.Worksheets.Cells;
Also, if you want to use any color which is not a part of Excel 2003 Default Color Palette in Excel 2003 file format, you may change the color palette. For details please check the following documentation link:
Thank You & Best Regards