Foreground color as an 8-character ARGB hex string (required).
OptionalbgColor: stringOptional background color as an 8-character ARGB hex string. If omitted, no background color is set.
A FillPattern object configured with type "pattern", pattern "solid", fgColor set to the given foreground color, and bgColor set if provided.
Creates a solid fill pattern object for use with Excel cell styling.