English: Visible spectrum against a D65 grey background as seen by people with normal color vision (middle), protanopia (top), and deuteranopia (bottom). The horizontal wavelength scale is 1nm per nominal pixel. Uses the CIE 2006 physiologically-relevant 2-degree LMS basis functions from http://www.cvrl.org/ciepr8dp.htm, the LMS-to-XYZ conversion from http://www.cvrl.org/database/text/cienewxyz/cie2012xyz2.htm, and the XYZ-to-sRGB formulas from the sRGB standard. The yellow and blue hues are the planes containing #AB8A00 and #0088C5, and are meant to approximate the hues that unilateral dichromats report seeing. The background is the darkest grey that brings everything into the sRGB gamut (which is unfortunately very bright). The result is not very pretty, but I think it's more accurate than anything else currently on Commons.