The present invention relates to a composition comprising a fluorescent material and a matrix material, a color conversion sheet and a light emitting diode device. The present invention further relates to the use of the composition in a color conversion sheet fabrication process, to the use of the color conversion sheet in optical devices or for agriculture purposes, and to the use of the fluorescent material and the matrix material in light emitting diode devices. Additionally, the invention relates to an optical device comprising the color conversion sheet and to a method for preparing the color conversion sheet and the optical device.