How can light affect peoples emotions and mood to contol how they feel ?

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I am designing a light for a project at University and I want to make a light that can provoke feelings in an environment. I want to use colour and I am thinking about using the colours of the rainbow. It will almost be like having the rainbow in your own home to give off positive feelings. Using colours can make an environment less intimidating. Would people like that? Or do you have any thought for ideas? I would like to use wood and Glass for the material Thanks!