A flickerless light source comprising a transparent or semitransparent diffuser, at least two lightpipes with patterned surfaces inside the diffuser, a single sided LED light source attached to each end of the diffuser, and a dual sided LED light source connecting the lightpipes together is disclosed. The patterned surface of the lightpipes diffuse or reflect light emitted by the single and dual LED light sources and through the lightpipes to provide a light with uniform brightness and intensity. The lightpipes are coated with a thin layer of visible-light transparent material which is doped with organic dye molecules. The organic dye has strong ultraviolet light absorption characteristics. By changing the doping concentration of the dye molecules the coating can become totally opaque or semi-transparent to certain wavelengths and selective wavelength conversion is obtained. In this way light color, brightness, and intensity can be varied or controlled.