Set the current color space and color. The parameter type can be "fill", "stroke",
or "both" to specify that the color is set for filling,
stroking or both filling and stroking. The parameter colorspace can be gray, rgb, cmyk, spot or pattern. The parameters c1,
c2, c3 and c4 represent the color
components for the color space specified by colorspace. Except as otherwise
noted, the color components are floating-point values that
range from 0 to 1.
For gray only c1 is used.
For rgb parameters c1,
c2, and c3 specify
the red, green and blue values respectively.
For cmyk, parameters c1,
c2, c3, and c4 are the cyan, magenta,
yellow and black values, respectively.
For spot, c1 should be a spot color handles
returned by pdf_makespotcolor() and c2 is a tint value between 0 and
1.
For pattern, c1 should be a pattern handle
returned by pdf_begin_pattern().