Shortest wavelength: Violet
In the visible spectrum the shortest wavelength is of violet. Violet is right before ultraviolet in the spectrum. And according to the wave equation (i.e. speed= frequency * wavelength), frequency is inversely proportional to wavelength so shortest wavelength means higher frequency as a result it has higher energy.
The longest wavelength is of the color red. As per the Wave equation (i.e. speed= frequency * wavelength), frequency is inversely proportional to wavelength so red having the longest wavelength has a lower frequency.
The colors from shortest to longest wavelength:
Violet
Blue
Green
Yellow
Orange
Red
Whilst white light is the mixture of the colors of the visible spectrum
