Neuroscience, frequencies, and perception

Everything has a frequency. Green is in the middle of the colour spectrum, I was told by a great college lecturer way back in 1988 that green has a frequency in the middle of the colour spectrum because many moons ago green was the abundant colour and so it takes less brain-ache for want of a better phrase to perceive that colour so setting the bias. This is why paint catalogues state that green has the most calming effect as it gives the noggin less work to do. Red is a colour frequency that stimulates brain activity and so acts as a warning.