For the Element of Harmony, see the appropriate section of the Elements of Harmony article. My Little Pony Friendship is Magic possesses many fantasy elements. A prominent one is the use of magic by ponies and other creatures such as changelings. Throughout the show, Earth ponies tend to crops and care for plants and animals, particularly in Winter Wrap Up, Fall Weather Friends, and Hearth's Warming Eve.
Visible light is merely a small part of the full electromagnetic spectrum, which extends from cosmic rays at the highest energies down through the middle range (gamma rays, X- rays, the ultraviolet, the visible, the infrared, and radio waves) all the way to induction-heating and electric-power-transmission frequencies at the lowest energies.
Violet (purple) is the highest energy color in the visible spectrum. It has a wavelength of about 400nm (4x10-8m), the lowest of all visible light.