Red


 * Red** is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm .[2 ] Longer wavelengths than this are called infrared (//below red//), and cannot be seen by the naked human eye . Red is used as one of the additive primary colors of light, complementary to cyan , in RGBRYB color space but not CMYK color space . In human color psychology , red is associated with bravery , purity , happiness , good luck , <span class="wiki_link_ext">heat , <span class="wiki_link_ext">energy , and <span class="wiki_link_ext">blood , and emotions that "stir the blood", including anger, passion, love, pain, and sacrifice.[5]