CairoPattern corresponding to an opaque color. The
color components are floating point numbers in the range 0 to 1.
If the values passed in are outside that range, they will be
clamped.cairoPatternCreateRgb(red, green, blue)redgreenblueCairoPattern] the newly created CairoPattern if successful, or
an error pattern in case of no memory.
This function will always return a valid pointer, but if an error
occurred the pattern status will be set to an error. To inspect
the status of a pattern use cairoPatternStatus.