My Indy (8 bit graphics) is paired up with an older NEC LCD display that does not support sync on green. To get around this I wired up the H and V sync pins from the 13W3 connector to the VGA connector. Now the monitor syncs up, but it has a green tint. The reason for this is that the sync signal is added to the green video signal by default, and this shifts the entire video signal up from ground by a few hundred mV. That confuses my monitor into thinking that green video is always on at ~50% level, resulting in the green tint. The sync signal is added to green by the RAMDAC chip, in this case BT445. There is a pin on that chip called SYNC# and according to the datasheet, tying that pin to GND would disable the sync and restore the green video level back to normal. (One would have to lift the pin on the BT445 and carefully solder it to GND to make this work.) Now if there is a way to do this in software or with some ENV command that would be cool, but at some point I'll look into doing this hardware mod to get rid of the sync on green.