Colour of sunlight : Light is a form of energy in the form of a wave that simulates that retina of our eyes. Visible light is a spectrum of a number of waves with different wavelength range from 400nm to 700nm (1nm = 10-9 metre) each wave has a definite wavelength represents a particular color. The band of visible light is VIBGYOR.
V - Violet
I - Indigo
B - Blue
G - Green
Y - Yellow
R - Red
Violet colour has shorter wavelength and red color has longer wavelength.
When light ray of particular wavelength (Colour) strikes the retina of our eye, our brain perceives that specific colour. When all colors of visible light strikes the retina of our eye at the same time, our brain perceives white.
Why is the word “AMBULANCE” written backwards in ambulance vehicle? This is due to lateral inversion .The phenomenon due to which the left side of an object appears to be right side of the object in its image in a reflecting medium (mirror). so that drivers see the word the right way around in their rear-view mirror
This shows, white is not a colour at all. But, it is the combination of all the colors of the visible light spectrum. If all the wavelength (colours) of visible light spectrum give appearance of white similarly, the observe of all there wavelength of visible light, will lead appearance of black