Hey, Sorry for the late reply. Been busy lately. Anyways, That happened to my too: when I put whites up front and reds rear.
For some strange reason the reds are brighter. Experimenting with different combinations of colors, I figured out that the voltage likes to go to the lower voltage rating LED.
For example, a Red LED is rated 1.85V and the white is 3.6V. Since it requires less voltage to power the Reds, the voltage likes to go there.
In conclusion, it's due to the voltage resistance of the lights. I tried putting a 10 ohm resistor on the reds and that seems to help out the voltage go to the whites.
I'm a bit lazy, er... busy to calculate the exact resistor value so use trial and error (I know it's more work, but it sure beats using my noggin
)
So here's how I would calculate this resistor voltage. I'd take the red voltage use the battery voltage and subtract it (3V-1.85V=1.15V) then use the 1.15 volts to calculate the resistance to limit the voltage from the battery to 1.15V to the red light.
It's just your basic resistance calulations. Won't go into too much detail. For more info on resistance calculations, go to my website (
http://www.geocities.com/mini_zracer/main) and click on the LED light section.
[edit]: I guess Shacky summarized this already
OHH one more important thing. Don't overload the battery with LEDs. The poor battery only supplies little amperage. So if you somehow load it up with like 4 superbrights, they will be all dim due to the massive pulling of all the lights. Better off using more batteries.