forceMono

Force printing in monochrome.
[read/write property] forceMono([out, retval] VARIANT_BOOL *mono) forceMono([in] VARIANT_BOOL mono)
If this property is set to true, XpdfPrint generates monochrome output, even if the printer appears to be color.

This setting is only relevant for GDI printing, i.e., for non-PostScript printers, or if forceGDI is true. It is ignored when XpdfPrint generates PostScript code.

resetParams resets this to its default value of false, which means to generate monochrome output for monochrome printers and color output for color printers.

VB6:
pdf.forceMono = True
forceColor
printerSupportsColor
resetParams