XLookupColor()															    XLookupColor()

Name
  XLookupColor - get database RGB values and closest hardware-supported RGB values from color name.

Synopsis
  Status XLookupColor(display, colormap, colorname, exact_def_return, screen_def_return)
	Display *display;
	Colormap colormap;
	char *colorname;
	XColor *exact_def_return, *screen_def_return;

Arguments
  display     Specifies a connection to an X server; returned from XOpenDisplay().

  colormap    Specifies the colormap.

  colorname   Specifies  a  color  name string (for example "red").  Uppercase or lowercase does not matter.  If the color name is not in the
	      Host Portable Character Encoding, the result is implementation-dependent.

  exact_def_return
	      Returns the exact RGB values for the specified color name from the /usr/lib/X11/rgb database.

  screen_def_return
	      Returns the closest RGB values possible on the hardware.

Returns
  Zero on failure, non-zero on success.

Description
  XLookupColor() looks up RGB values for a color given the colorname string.  It returns both the exact color values and the  closest  values
  possible on tthe screen specified by colormap.

  XLookupColor() returns non-zero if colorname exists in the RGB database or zero if it does not exist.

  To  determine  the  exact RGB values, XLookupColor() uses a database on the X server.  On UNIX, this database is /usr/lib/X11/rgb.  To read
  the colors provided by the database on a UNIX-based system, see /usr/lib/X11/rgb.txt.  The location, name, and contents of  this  file  are
  server-dependent.

  For more information see Volume One, Chapter 7, Color, and Appendix D, The Server-side Color Database, in this volume.

Errors
  BadName   Color name not in database.

  BadColor  Invalid colormap.

Structures
     typedef struct {
	 unsigned long pixel;
	 unsigned short red, green, blue;
	 char flags;	    /* DoRed, DoGreen, DoBlue */
	 char pad;
     } XColor;

See Also
  XBlackPixel(),  XWhitePixel(),  XAllocColor(),  XAllocColorCells(),  XAllocColorPlanes(), XAllocNamedColor(), XFreeColors(), XParseColor(),
  XQueryColor(), XQueryColors(), XStoreColor(), XStoreColors(), XStoreNamedColor().

Xlib - Color Cells														    XLookupColor()