You dont wanna have amber running lights in the rear, kinda illegal everywhere that I know of. There are however a few options. Custom Dynamics (customdynamics.com) has some real nice LED clusters that will set you up with not only red running and brake lights, but also amber turn signals, all in the same cluster. They are kinda expensive, but you might like them. They work best with clear or smoke lenses, but are bright enough to shine red through amber lenses too. Other wise, you will have to go with red LED's with red, clear or smoke lenses, which works just fine as well, though not quite as spiffy. They also have regular amber 1156 clusters with a right angle on them so they fit right in our old style taillights.
I use their 1.85" cluster for my brake light, and works very well.
Another option you might investigate is headlight or tail light modulators. Both increase visibility greatly, I have the "Back-Off" module for my taillight, and have never had anyone run up on me yet. I know, dont say "yet".
Sol
