The code for "text font color"
RGB Color is specified as RRGGBB
Theme Color is specified as TTSNN where TT is the theme color Id, S is either "+" or "-" of the tint/shade value, NN is the tint/shade value.
Namespace:
OfficeOpenXml
Assembly:
EPPlus (in EPPlus.dll) Version: 3.0.0.1 (3.0.0.1)
