Biologically derived fluorescent proteins are an attractive alternative to current color-conversion materials for solid state lighting applications, such as inorganic phosphors, organic dyes and nanocrystal quantum dots. Despite extensive research into fluorescent proteins for biological applications, they were not explored to be used for color-conversion for light-emitting diodes. In this study we investigate the in-solution characteristics of enhanced green fluorescent protein (eGFP) and monomeric cherry (mCherry) for LED applications. We demonstrate that these proteins can be used to completely convert the electroluminescence of a pump LED to photoluminescence. We show that up to typical pump driving current (150 mA) there is no saturation or bleaching of the proteins. Moreover, we compare the performance of in-solution unpurified and purified proteins as color convertors for LEDs and we show that unpurified fluorescent proteins in solution are suitable for color conversion applications.