XSetWMColormapWindows, XGetWMColormapWindows - set or read a window's
  WM_COLORMAP_WINDOWS property
Status XSetWMColormapWindows(Display *display, Window
    w, Window *colormap_windows, int count);
Status XGetWMColormapWindows(Display *display, Window
    w, Window **colormap_windows_return, int
    *count_return);
  - display
- Specifies the connection to the X server.
- colormap_windows
- Specifies the list of windows.
- colormap_windows_return
- Returns the list of windows.
- count
- Specifies the number of windows in the list.
- count_return
- Returns the number of windows in the list.
- w
- Specifies the window.
The XSetWMColormapWindows function replaces the WM_COLORMAP_WINDOWS
  property on the specified window with the list of windows specified by the
  colormap_windows argument. It the property does not already exist,
  XSetWMColormapWindows sets the WM_COLORMAP_WINDOWS property on the
  specified window to the list of windows specified by the colormap_windows
  argument. The property is stored with a type of WINDOW and a format of 32. If
  it cannot intern the WM_COLORMAP_WINDOWS atom, XSetWMColormapWindows
  returns a zero status. Otherwise, it returns a nonzero status.XSetWMColormapWindows can generate BadAlloc and
    BadWindow errors.
The XGetWMColormapWindows function returns the list of
    window identifiers stored in the WM_COLORMAP_WINDOWS property on the
    specified window. These identifiers indicate the colormaps that the window
    manager may need to install for this window. If the property exists, is of
    type WINDOW, is of format 32, and the atom WM_COLORMAP_WINDOWS can be
    interned, XGetWMColormapWindows sets the windows_return argument to a
    list of window identifiers, sets the count_return argument to the number of
    elements in the list, and returns a nonzero status. Otherwise, it sets
    neither of the return arguments and returns a zero status. To release the
    list of window identifiers, use XFree.
XGetWMColormapWindows can generate a BadWindow
    error.
  - WM_COLORMAP_WINDOWS
- The list of window IDs that may need a different colormap from that of
      their top-level window.
  - BadAlloc
- The server failed to allocate the requested resource or server
    memory.
- BadWindow
- A value for a Window argument does not name a defined Window.
XAllocClassHint(3), XAllocIconSize(3), XAllocSizeHints(3), XAllocWMHints(3),
  XFree(3), XSetCommand(3), XSetTransientForHint(3), XSetTextProperty(3),
  XSetWMClientMachine(3), XSetWMIconName(3), XSetWMName(3), XSetWMProperties(3),
  XSetWMProtocols(3), XStringListToTextProperty(3)
Xlib - C Language X Interface