English: Linear representation of the visible spectrum. The XYZ coordinates were taken from the CIE homepage. The method used to calculate the RGB values are adopted from File:Linear visible spectrum.svg, i.e. doing a binary search along a constant-hue line from the spectral colour point to the RGB gamut border. In contrast to the method in that image the spectral colour was taken every 1 nm, and the brightness was not decreased towards the grey axis. The spectral intensity was weighted with a 10000 K blackbody spectrum since the projection onto the sRGB gamut somehow suppresses part of the blue. In addition, a gamma correction of 1.2 was applied in the linear RGB space to enhance the visibility at the violet and red ends. The brightness profile is an interpolation between the actual spectral brightness and a Gaussian profile centered at 555 nm with sigma=50 nm in order to reduce the somewhat artificial-looking brightness gap between blue and green. Finally, a Gaussian blur with sigma=7nm was applied to smooth the remaining jumps in chromaticity. The scale indicates the (approximate) wavelength in nanometres.