Reducing the voltage to an LED does not change the color output, or warmth, of the fixture. LEDs are designed to emit the same color at all points of voltage.
If your goal is to alter the output of your LED fixture, we do offer various options. Filters are available for our .500 LED fixtures to alter the output between 2700K warm white (incandescent equivalent), 3000K pure white (halogen equivalent), and 4200K cool white (fluorescent equivalent). Our .550 LED fixtures emit 2400K ultrawarm white, which is comparable to the warmth of candlelight.