Dont buy orange or yellow Leds, waste of time, use bright white under these insert colours and u cant go wrong.
Red for red, purple for purple, green for green, white for clear and so on. Somebody else said pinball-life and i have gone that way as well, always in bulk.

G.I lighting is great to do with bright white, i never bother with flashers, no need unless u want to go from white to a colour. Ghost roms are avail ofcourse, machine dependant.  Have fun with it.

I agree with the orange/yellow comment. The white gives a better orange and yellow result. although I went ballistic with leds I have changed my ways with it. I think GIs are best candescent and too  much leds can detract from the gameplay. A little blinding for me. I have used 3 leds primarily to form this opinion.