I came across this very interesting information a few months ago and I am glad to find it again. UuU Not much is mentioned but I believe it gives a simple and clear inside of how colour relates to our emotional reaction towards things.
Colour Psychology
My favourite out of all the information it provides
More information about Colour Psychology and Colour Perception

Looking at it from a scientific view point, through our eyes, our brain interprets electromagnetic radiation of different wavelengths within the visible spectrum. Colours are just different wavelengths we see and interpret using our brain. Visible light lies between 400-700 nano-meters for the human eyes. Wavelength exceeding 750 nm is known as infrared; wavelength below 350 nm is known as ultraviolet.
Extra information, how animals perceive the world around them, much different from humans
Visions in different animals