Final post on the Prismatic color model

This is the last in a series of posts on the Prismatic color space Dave Hart and I produced for the Subjective iPhone photo editing app.   I have written previously on the "Zorn" palette.   Here I will show doing color grading to it by projecting to its hue boundaries which gives a good idea of how one might use the barycentric hue space.

If we assume red, yellow, and neutral as our primaries this means we want to restrict our hues to this triangle:

 There are lots of ways to project hues to that triangle, with this one being better at projecting greens to yellows which is less disruptive in practice:

The Zorn palette is usually used when there is no blue (like a sky) but let's do it out of its comfort zone for fun: