LED Replacement - revisited

[mbeach]

Experiment here.
High-intensity LEDs will all appear clear -the color comes from doping in the semi-conductor material. They will not have the tinted appearance of the old LEDs.
Your highest lux rating will come from some very expensive LEDs -Luxeon Stars and the like. They can be purchased in strips, that are already pre-wired.
Less expensive options can be had, but they will require your time to mount them on perf board, figure up the voltage drop, etc.

I'd rig up a string of white high-intensity LEDs and place them behind your lenses to get a feel for the color. White LEDs behind red filters may appear orange-ish, or they may be just what you are looking for. It'll be tough to match the tint/color of the 3rd brake light, but that would be the best look I'd say. My guess is that they used a slightly orange (lower wavelength) red LED coupled with the red filter lenses to get that vibrant red on the 3rd lamp.

Visit superbrightleds.com for inspiration.

EDIT:
Another important consideration, viewing angle. Most high-intensity LEDs have a 20* viewing angle. If mounted on a curve, this is O.K., but if mounted 90* to the roadway, they will be invisible from the side, especially during daylight. That tailgating motorcycle may never see your turnsignal.
See FMVSS 108 for details on viewing angle requirements.

[Moncha]

I've played with the different combinations of colors and found using the same color of LED with the lens works best.. The white LEDs seemed to make the lens color funky in my opinon.. The white LED with red lens, when lit would produce kind of a purple color.. Was not to my taste. The white LED with yellow lens would just wash out the color so much it was butt ugly.
The equilizers are an old tech way of taking care of the flasher prob.. Go with the new electronic flashers. You won't "save" any power using the equilizers per se, because the equilizers draw the same amount of power as the regular bulbs.
The tower LED replacements I found solve the viewing angle problems.