Err, sorry but led colour is determined by mix of chemicals inside not voltage. And after a bit of training soldering these by hand is a piece of p**s I do it all day some days 0603 or 0402 refers to size in thousandths of an inch therefore 6 thou by 3 etc. So you could change colour reasonably easily if you can get LED's and can solder them! If anyone feels like taking dash apart, sourcing LED's and sending me both then for a pint I'll solder! Only small issue may be resistor used to supply correct voltage to each one, some colours need higher or lower, white usually needs higher, cos of way they work but if just changing red to green you should be fine!