Source:http://linkedlifedata.com/resource/umls/id/C1313858
NCI: The hue of that portion of the visible spectrum lying between red and yellow, evoked in the human observer by radiant energy with wavelengths of approximately 590 to 630 nanometers; any of a group of colors between red and yellow in hue, of medium lightness and moderate saturation. (American Heritage Dictionary - Bartelby.com)