Defines a color mask.
A color mask specifies a range of colors to be masked out.

Initializes a new PDFColorMask object.

Gets the end of the colors range.
The colorspace of startColor must match the colorspace of end color and also the image's colorspace.

This method supports the internal library infrastructure and should not be used by external client code.

Gets the start of the colors range.
The colorspace of startColor must match the colorspace of end color and also the image's colorspace.

Sets the end of the colors range.
The colorspace of startColor must match the colorspace of end color and also the image's colorspace.

Sets the start of the colors range.
The colorspace of startColor must match the colorspace of end color and also the image's colorspace.