A lighting system includes a helical light-transmitting fiber and an LED. The helical light-transmitting fiber is doped with a first wavelength converting material and defines a helical axis. The LED has a light-emitting portion for emitting light of a first color. The LED is aligned axially with the first helical fiber such that a portion of any light emitted by the LED will pass through the open space between the turns of the first helical fiber and a portion of any light emitted by the LED will be received by the first helical fiber and converted to light of a second color. Adjustment of the compression of the helical fiber will adjust the mixture of colors in the light emitted by the system. Further, the relatively small cross-sectional area of the fiber serves to lessen any dye migration in the fiber.