You can also use Radio Shack part number 272-1092 mini 12 volt bulbs, $2.49 for a pack of two is what I paid last week. You have to pull the old bulb out of the plastic holder and reuse the holder as well as the colored cap. The bulbs are not colored, they have colored caps on them that you can carefully slide off and put on a new bulb. The wires just wrap around the holders, no soldering required. I just did this with maybe 12 of them, a lot were burned out on my disco.
The ones I see on the Rovers North site, RNE752, are $3.59 each. So the Radio Shack route is quite a bit cheaper if you have several to replace.