Answer:
Violet
Explanation:
Electromagnetic waves consists of oscillating electric and magnetic fields that vibrate in a direction perpendicular to the direction of propagation of the wave (for this reason, these waves are also called transverse waves).
Electromagnetic waves are generally invisible to human eye, apart from a very small portion of it, called visible light.
Waves in the visible part of the spectrum appear to us as a different color, depending on their wavelength. From shortest to longest wavelength, we have:
Violet (380-450 nm)
Blue (450-495 nm)
Green (495-570 nm)
Yellow (570-590 nm)
Orange (590-620 nm)
Red (620-750 nm)
So we see that violet is the color with shortest wavelength.
