void pdf_setcolor
(int pdf object, string type, string colorspace, float c1 [, float c2 [, float c3 [, float c4]]])
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().