When none carried out a “difference” analysis of the 2004 DVD and the 2011 BD he came up with this list of visual changes:
http://originaltrilogy.com/post/id/538958

?00:07:54 - : Lightsaber cores?
00:33:18 - 00:33:27 : Bottom half of Jedi temple has been revised
00:38:05 - : Coruscant sun, more intense
00:48:28 - 00:48:30 : Kashyyyk sky intensity change, Roofs revised
?00:49:11 - : top half of frame dif or just window?
00:53:31 0 : Coruscant sky
?01:03:58 : top frame change?
01:23:01 - 01:23:07 : Kashyyyk building roof color change
01:23:10 - : Kashyyyk building interior windows brighter
01:40:26 - : Weird Obi sunlight modification
01:41:43 - : Color shift to Padme’s ship