I replaced my bad bulb with a Mini Christmas tree, flasher, 12v bulb. You may have to bust the old bulb and solder the leads of the Mini bulb to the filament wires of the old bulb base or wire in a Mini socket into the original socket. I did not say it was painless!
If you get one that is colored and you want clear, scrap off the colored paint. I use dozens of mini Christmas tree lights for all my building lights as they are inexpensive and use very little power. Ebay is the best source now as stores like Walmart, CVS and Target do not sell Christmas items now.
Charlie