Sets the colour used for filling (g, rg, k, or cs and sc/scn).
public void SetFillColor(PdfColor color)
The colour: a value in a device space, or in a space of this document (GetColorSpace(CosObject), CreateIccBasedColorSpace(ReadOnlySpan<Byte>), CreateSeparationColorSpace(String, PdfColor), CreateDeviceNColorSpace(IReadOnlyList<String>, IReadOnlyList<PdfColor>)).
ISO 32000-2 §8.6.8, Table 73. Device colours use the operator of their family, which also selects the space. Any other space is
named in the ColorSpace resources and selected with cs when it is not the current one; its components are set with
scn (ICCBased, Separation, DeviceN) or sc. The space's minimum version is recorded (Table 61).