OptionalbackgroundMints the cell the pattern CSS is read from — the model owns the tile geometry, so a swatch without a workbook to ask has nothing to draw.
OptionaldarkWhether to bake the colors for a dark surface.
OptionalforegroundThe color of the tile's marks — Excel's Pattern Color.
The tile to draw.
The color behind the marks — Excel's Background Color, and all of a
solidtile.