XCreateColormap, XCopyColormapAndFree, XFreeColormap, XColor - create, copy, or destroy colormaps and

alloc     Specifies the colormap entries to be allocated.  You can pass AllocNone or AllocAll.

       colormap  Specifies the colormap that you want to create, copy, set, or destroy.

       display   Specifies the connection to the X server.

       visual    Specifies a visual type supported on the screen.  If the visual type is not  one  supported  by
                 the screen, a BadMatch error results.

       w         Specifies the window on whose screen you want to create a colormap.

       The  XCreateColormap function creates a colormap of the specified visual type for the screen on which the
       specified window resides and returns the colormap ID associated with it.  Note that the specified  window
       is only used to determine the screen.

       The  initial  values of the colormap entries are undefined for the visual classes GrayScale, PseudoColor,
       and DirectColor.  For StaticGray, StaticColor, and TrueColor, the entries have defined values, but  those
       values  are specific to the visual and are not defined by X.  For StaticGray, StaticColor, and TrueColor,
       alloc must be AllocNone, or a BadMatch error  results.   For  the  other  visual  classes,  if  alloc  is
       AllocNone,  the  colormap  initially  has  no  allocated  entries,  and  clients  can allocate them.  For
       information about the visual types, see section 3.1.

       If alloc is AllocAll, the entire colormap is allocated writable.  The initial  values  of  all  allocated
       entries  are  undefined.   For  GrayScale  and  PseudoColor, the effect is as if an XAllocColorCells call
       returned all pixel values from zero to N - 1, where N is the colormap  entries  value  in  the  specified
       visual.   For  DirectColor,  the effect is as if an XAllocColorPlanes call returned a pixel value of zero
       and red_mask, green_mask, and blue_mask values containing the same bits as the corresponding masks in the
       specified visual.  However, in all cases, none of these entries can be freed by using XFreeColors.

       XCreateColormap can generate BadAlloc, BadMatch, BadValue, and BadWindow errors.

       The XCopyColormapAndFree function creates a colormap of the same visual type and for the same  screen  as
       the  specified  colormap  and  returns  the  new colormap ID.  It also moves all of the client's existing
       allocation from the specified colormap to the new colormap with their color values intact and their read-
       only or writable characteristics intact and frees those entries in the specified colormap.  Color  values
       in  other entries in the new colormap are undefined.  If the specified colormap was created by the client
       with alloc set to AllocAll, the new colormap is also created with AllocAll,  all  color  values  for  all
       entries are copied from the specified colormap, and then all entries in the specified colormap are freed.
       If  the  specified  colormap was not created by the client with AllocAll, the allocations to be moved are
       all those pixels and planes that have been allocated by the client using  XAllocColor,  XAllocNamedColor,
       XAllocColorCells, or XAllocColorPlanes and that have not been freed since they were allocated.

       XCopyColormapAndFree can generate BadAlloc and BadColor errors.

       The  XFreeColormap function deletes the association between the colormap resource ID and the colormap and
       frees the colormap storage.  However, this function has no effect on the default colormap for  a  screen.
       If  the  specified colormap is an installed map for a screen, it is uninstalled (see XUninstallColormap).
       If the specified colormap is defined as the colormap for a window (by XCreateWindow,  XSetWindowColormap,
       or  XChangeWindowAttributes),  XFreeColormap  changes the colormap associated with the window to None and
       generates a ColormapNotify event.  X does not define the colors displayed for a window with a colormap of
       None.

       XFreeColormap can generate a BadColor error.

BadAlloc  The server failed to allocate the requested resource or server memory.

       BadColor  A value for a Colormap argument does not name a defined Colormap.

       BadMatch  An InputOnly window is used as a Drawable.

       BadMatch  Some  argument  or  pair of arguments has the correct type and range but fails to match in some
                 other way required by the request.

       BadValue  Some numeric value falls outside the range  of  values  accepted  by  the  request.   Unless  a
                 specific  range  is specified for an argument, the full range defined by the argument's type is
                 accepted.  Any argument defined as a set of alternatives can generate this error.

       BadWindow A value for a Window argument does not name a defined Window.

       XCreateColormap,  XCopyColormapAndFree,  XFreeColormap,  XColor  - create, copy, or destroy colormaps and
       color structure

XAllocColor(3), XChangeWindowAttributes(3), XCreateWindow(3), XQueryColor(3), XStoreColors(3)
       Xlib-CLanguageXInterface

X Version 11                                      libX11 1.8.12                               XCreateColormap(3)

       The XColor structure contains:

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

       The red, green, and blue values are always in the range 0 to 65535 inclusive, independent of  the  number
       of  bits actually used in the display hardware.  The server scales these values down to the range used by
       the hardware.  Black is represented by (0,0,0), and white is represented by (65535,65535,65535).  In some
       functions, the flags member controls which of the red, green, and blue members is used  and  can  be  the
       inclusive OR of zero or more of DoRed, DoGreen, and DoBlue.

       Colormap XCreateColormap(Display *display, Window w, Visual *visual, int alloc);

       Colormap XCopyColormapAndFree(Display *display, Colormap colormap);

       int XFreeColormap(Display *display, Colormap colormap);