the bulbs themselves arent green, theres coloured clear plastic inside the instrument cluster. led mods can be difficult because leds are directional, you can put brighter leds in and just end up with brightly lit spots.
you pretty much have to upen the cluster up and strategically position all your leds, and youll also need resistors on the leds so they dont blow up.
alternatively, just remembering, you can get led units which are a straight swap for 12v wedge bulbs like the general illumination bulbs in your dash. the warning lights are small bulbs, you probably wont find led versions.
you could try the led conversion bulbs.