As an FYI, I installed the Kuryakyn #4859 on my FXSTDSE2 and ran into the same issues with regards to the rear turn signal bulbs. On the first day with the stock ambers, I got pulled over, so I figured I better get this resolved quickly.
I did a ton of searches for Red 1156 bulbs and did order the 10 pack from the guy on Ebay. Unfortunately, those bulbs look almost pink next to the deep rich red of the stock tail lamp.
Next, I tried buying a set of those red colored bulb covers and those on top of the red bulbs helped create a deeper red. The problem was, the covers add a weird effect to the bulbs with the reflector, which is a little hard to explain, but it looked ridiculous.
Finally, I just ran to the HD dealer and bought the red lens from the kit mentioned above with clear bulbs and it looks pretty good. At least the red matches pretty good across all three lamps. And, the rear visability at night is a remarkable improvement.
While I still would love to find some red bulbs that will work with the stock smoked lenses, until I find something, this set up works pretty good and will keep the cops off my back. I have thought of smoke tinting the red lens too, but I'll hold off on that as a last resort. Hopefully, I stumble on some decent red bulbs somewhere.