Novel compositions and methods of using those compositions to form high refractive index coatings are provided. The compositions comprise a mixture of two silicone polymers, a catalyst, and an inhibitor for the catalyst. The preferred catalyst comprises platinum. Unlike prior art silicone systems, the inventive composition can be provided in a one-part form due to a substantially improved pot life. The compositions can be spin- or spray-applied, followed by baking to crosslink the polymers and form a cured layer. The inventive cured layers have high refractive indices and light transmissions.