Red with red will be brighter. The following is stolen from superbrightleds.com:
Which Color LEDs should I use ?
For best results the LED color should be the same as the lens color. As an example: a red lens will filter out all but the red portion of the light so if the light is all red, none or very little light will be blocked by the lens. The light from a White LED contains very little light in the red portion of the visible spectrum so most of the light would be filtered out by a red lens.
Turn signal issues with LED bulbs
LED brake/tail lamps will not flash with thermal flasher units due to their extremely low current draw. Also, with stock flasher units, the turn signals may flash faster than normal (Hyper-Flash).
These installations will require an electronic flasher unit, available in our car bulb shopping category (for some vehicles) or at your auto parts store. Try to find flashers designed to work with LED bulbs, they will say "LED compatible". Often HEAVY DUTY flashers will also work with LED bulbs.
We offer some LED Flashers in our Tail/Brake Turn Signal Bulb category but we do not know which one (if any) will fit your vehicle. You will have to compare the pin-out of your flasher with the pin-outs of the flashers we offer, to see if we have a match, BEFORE you order one. Sorry but we do not have a flasher application list or the expertise to tell you which of our flashers will fit your vehicle.
Another fix is the installation of Load Resistors which are wired across (in parallel with) the turn signal bulbs to simulate the load of a standard filament bulb. We also have these available in our car bulb shopping category.
Dash indicators reporting burnt out bulbs
LED bulbs may cause some newer vehicles to indicate a bulb is burnt out (because of their low power consumption). Some cars indicate this by increasing the flash rate of the turn signals, some turn on a bad bulb indicator. The only fix for this is to install Load Resistors across the bulbs that are being indicated as bad. Some vehicles will also disable the cruise control system if a brake light bulb is being indicated as bad, the installation of Load Resistors will also solve this problem.
Brightness of LED Car Bulbs
LED bulbs are generally not as bright as standard incandescent bulbs, they have many advantages over filament bulbs (longer life, faster on/off times, lower power consumption, more vivid colors) but brightness is not one of them.
They are generally not as bright but some of them with large numbers of LEDs, will appear brighter than filament bulbs.
As an exception, our new 3 Watt and 5 Watt Luxeon LED car bulbs are as bright or brighter than most standard filament car bulbs.
The light is distributed differently so they can appear brighter in some applications and not as bright in others, it depends on the size and shape of the bulb housing and reflector.
Most LED bulbs emit light like a flashlight, all out the end. Regular filament bulbs emit light from the end and all sides, so they will be better suited for some lighting applications than LED bulbs.
This is the same reason why we do not rate LED car bulbs in lumens or watts, the numbers would be deceptively low because the light is measured from all sides and the end on standard filament bulbs but only from the end on LED bulbs
What is the difference between Warm White and Cool White?
Warm white and cool white have two different correlated color temperatures which are measured in Kelvin.
Warm white (2500K~4000K) resembles incandescent light bulbs, cool white (5000K~8000k) resembles fluorescent light bulbs.
CLICK TO SEE PHOTO COMPARISON
Which LEDs bulbs are brightest?
Our 3 Watt and 5 Watt Luxeon LED bulbs are by far the brightest we offer.
Some of our bulbs are available with 12, 19, 24 or 30 LEDS, the more LEDs they have, the brighter they are.
CLICK HERE TO SEE OUR WHITE LED CAR BULB COMPARISON CHARTS
Are your bulbs standard size?
All of our Tail/Brake lights are the standard one inch diameter except for the 30-LED units. They are 1-5/8 inch diameter so please measure to make sure they will fit in your housings. All of our car bulb types have a "more info" button near them, click these buttons to see dimensional drawings and other specifications.
What is the difference between Narrow and Wide viewing angle ?
Some of our bulbs are available with Narrow or Wide viewing angle. The Wide angle (approx. 100 degree beam) will light up more area but dimmer than the Narrow angle. The Narrow angle (approx. 15 degree) will illuminate a smaller area but brighter than the Wide angle. We also offer bulbs with some LEDs aiming out the end of the bulb and some radially mounted LEDs aiming out the sides of the bulb. These will provide a more complete and even light pattern on the vehicle lens.
We cannot recommend which type would work best in your vehicle because it depends on the size, shape and depth of your bulb housings. The Wide angle bulbs usually work best for most vehicles.
How do your LED bulbs achieve dual intensity?
All of our Tail/Brake bulbs achieve dual intensity modes by turning all of the LEDs on dim or all of the LEDs on bright, all of the LEDs are always lit when either mode is active.
If I install LED bulbs in the dash, will the dimmer still work?
Yes, LED bulbs will dim with your dash light intensity control
Warranty Information
Do not use LED bulbs in the same housing with head lamps, the heat will cause them to fail quickly and void the warranty.
We warrant all of our bulbs for one full year when if used in normal vehicle applications.
We do not warrant our car bulbs when used in applications other than normal vehicle bulb installations or if used in headlamp housings or to replace GM Daytime Running Lights
Some GM vehicles apply a pulsed voltage to the Daytime Running Lights (DRL), this pulsed voltage causes LED bulbs to fail quickly, just as the stock filament bulbs also fail quickly in these DRL installations. Use in these applications voids the warranty.