256 RGB Matrix with fastled

You can't use names but you can use pointers (addresses).

uint32_t * Xitems[77] = {
  Xmas001 , Xmas002 , Xmas003 , Xmas004, Xmas005 ,
.
.
.
 Xmas073, Xmas074, Xmas075, Xmas076, Xmas077
};

You would then fetch the pixel with:
pgm_read_dword(&(Xitems[frame][i]));