You can change the bulbs to any color you want but the problem is that the numbers and hash marks on the gauge face are colored the greenish blue that you see them light up when you have your lights on at night. The only color that might work and not look funny would be to get some blue incandescent bulbs or blue led replacements. The thing with leds is that they will put out a lot more light, but it is a very focused beam and can cause the areas directly in front of the bulb to be much more bright than areas of the gauge face that don't have a bulb directly behind them.
I haven't taken apart a Liberty cluster to see how the gauge face is out together, but it might be possible to take the gauge face itself off of the piece of clear plastic it is mounted on and remove the greenish blue coloring from the back of the gauge face, thereby allowing you to choose any color you want. But thats just from my experience with Dodge Stratus/Chrysler Cirrus/Plymouth Breeze clusters and the fact that a lot of mopar parts, like clusters, are made in basically the same way. I cannot guarantee that the latter suggestion will work but give it a shot and maybe you'll get lucky.