I have a question: Is it possible to create visible light using two other non-coherent waves from the electromagnetic spectrum for example superposing infrared and ultraviolet to create visible light?
Color vision is based on the response of cone cells in the eye to different frequencies of light. For humans (with full color vision) there are three types of cones sensitive to different frequency ranges at different levels. Each individual photon in your superposed wave will be of a specific frequency, which for your question you've assumed is outside the visible range, i.e. outside the sensitivity region of any of the cones. Hence even if one of those photons hits a cone cell, it will not generate a response at the cellular level and will therefore not be perceived by the brain at all. It doesn't matter how many different frequencies of photons you superpose - if none of them are in the visible range then none of them will stimulate any of the cones.