elm-linear-sRGB
The standard RGB encoding (sRGB) is the colorspace currently in use by the vast majority of programs and websites. This encoding is not linear with respect to the perceived lightness of the resulting color by the human eye. One consequence of this is that (linear) interpolations between two sRGB-encoded color values tend to produce murky intermediary colors with varying perceived lightness, since the color values have already been non-linearly transformed to sRGB.
In contrast, after decoding sRGB values back to the CIE RGB space, linearly interpolating between the red, green and blue components yields colors that all share the same perceived brightness.
Visual comparison
In the above screenshot, the upper interpolation is the current 'standard' interpolation applied to the sRGB-encoded values. The lower interpolation is the interpolation applied after decoding the sRGB to (linear) CIE-space.
Documentation
This package currently exports a single utility function that performs the respective decoding and re-encoding from and to sRGB internally and yields true linear interpolations between the given sRGB-encoded colors. The integer argument determines the number of colors to be produced between the given start and endpoint.
linearInterpolation : SRGB -> SRGB -> Int -> List SRGB
type alias SRGB = (Float, Float, Float)