```
ChromaticityPlot3D("LCH", "LAB", Mesh -> None, Boxed -> False,
Axes -> False, PlotPoints -> 50)
RegionPlot3D({x^2 + y^2 < 1 && 0 <= z <= 1}, {x, -1, 1}, {y, -1, 1}, {z, 0, 1},
ColorFunction -> (LABColor(#3, #1, #2) &),
ColorFunctionScaling -> False, Mesh -> None, Boxed -> False,
Axes -> False, PlotPoints -> 50)
```

both give the same results. I am trying to create sections like this

```
RegionPlot3D({x^2 + y^2 < 1 && 0 <= z <= 1 && x < y},
{x, -1, 1}, {y, -1, 1}, {z, 0, 1},
ColorFunction -> (LABColor(#3, #1, #2) &),
ColorFunctionScaling -> False, Mesh -> None, Boxed -> False,
Axes -> False, PlotPoints -> 50)
```

but its slightly off, and I’m haveing trouble rotating it to cover all hues. I’d ultimately like to be able to take a cylindrical segment using the colour function as above, but have not had any luck so far (I won’t post my failed attempts!). Any ideas how I might achieve this?