As a warning, this would not be good for colorblind people (such as myself). The "Hello, Hacker News!" Hash's middle ring has half it's ring that looks identical to me, and unless I looked carefully, that entire ring looked the same to me.
What would you suggest as a solution ? I considered swapping Hue for Lightness in order to increase contrast changes. Would you be interested in testing out some variants ?
You could apply repeating surface textures inside each slice, rather than showing a solid color, so that Hue 1 shows repeating dots, Hue 2 shows repeating lines, Hue 3 shows repeating triangles.
You could use a Braille-like 2x2 grid to represent the 4-bit Hue space as circles and lines within each slice.
If you imagine that each slice has 4 walls, replacing the missing fourth wall of the innermost slices with the innermost corner, then you could map the binary representation of 2^4 hue (such as 0110) onto "bites" out of the walls. For example, given 0110, map the 0s onto "bites" and punch a small hole into two adjacent walls of the slice; given 0000, punch a small hole into all four walls.
ASCII art of what I mean by "punch a hole into the wall", for Hue 0111 (one zero, so one hole punched). This is an uncurved slice, because ASCII art.
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