For , fluoride ions as ligands cause such a small splitting that the six outer electrons in can spread out among both levels to produce a high-spin complex with four unpaired electrons (see right). absorbs radiation of low energy red wavelengths, and thus is green. Ammonia is a stronger ligand, and produces a large enough splitting to keep all six electrons paired in the , , and orbitals, which point away from the lone pairs of the ammonia nitrogens. When electrons are promoted to the upper e state in blue light is absorbed, thereby giving solutions of the complex a yellow-orange hue. Because the cyanide ion, , is a strong ligand, capable of producing a large splitting, absorption for occurs in the ultraviolet. The small tail of absorption extending into the violet region gives solutions a washed-out yellow cast.