You get orange by mixing red and green light, so at the very least you have the option of re-soldering the wires to give you either a red or a green blade.
My understanding is that all mixed colours are produced using an RGB LED unit, so you may also be able to change the wires over to get purple (equal red and blue), pink (red and resistored blue), blue, light blue (blue and green) and so on.
I did this with a purple 'sabre I had to get pink -
http://www.saberforum.com/index.php?topic=17749.0 for some details.
Otherwise you can order a replacement LED module, as Wolfknight and Kouri say, and wire it in yourself.