To make threads easier to track, it might be good to alternate slightly lighter and darker bg colours per poster

[Omnikron13]

Additionally, if usernames were hashed and that hash used to generate a colour within certain bounds, it could make it a lot easier to track threads by recognising the colour of the names you're talking to.

An xxhash is very quick and gives you at least 64 bits to divide up over some subset of a chosen colour space. I believe there are some good packages for HSL, HSV, etc. etc.

Packages like this one support all manner of colour profiles, some of which like HSLuv are very good for generating a range of colours which appear similarly bright/saturated/etc. as you shift around whatever subset of them.

You probably only want about 5 bits for +-16 swing either side of about 60 for saturation and 5 more for luminosity, and then the hash leaves 54 bits for the 360 degree hue, though you'd only really need 24 or 32 or something. One possible hash of my handle could be: taking 24 bits for hue:

Of this taking 32 bits:

The first 42-bits of the xxhash of a given user could give them a predictable coloured username as you're going over threads.

I'd take 5-bits for +-16 around 60 sat, 5-bits for +-16 around 60 luv, and 32 bits as the 0-360 hue, personally.

(I took the bits from the left hand side of the hash, but I suppose it would probably be better to take 5, bitshift, take 5, bitshift and take 32 from the right hand side...)

[Omnikron13]

package main

import (
	"fmt"
	"image/color"
	"math/bits"

	"github.com/cespare/xxhash"
	gc "github.com/lucasb-eyer/go-colorful"
)

func main() {
	c := get_hsluv("Omnikron13")
	r, g, b, a := c.RGBA()
	fmt.Printf("RGB: %#v%0x%0x, A: %0x\n", r>>8, g>>8, b>>8, a>>8)
}

func get_colour(s string) (sat uint64, luv uint64, hue float64) {
	const mask5bit = 0b11111
	const mask32bit = 0xFFFFFFFF
	hash := xxhash.Sum64String(s)
	sat = hash & mask5bit
	hash = bits.RotateLeft64(hash, -5)
	luv = hash & mask5bit
	hash = bits.RotateLeft64(hash, -5)
	hue = float64(hash&mask32bit) / float64(mask32bit) * 360
	return
}

func get_hsluv(s string) (c color.Color) {
	sat, luv, hue := get_colour(s)
	c = gc.HSLuv(hue, float64(sat+28)/100, float64(luv+28)/100)
	return
}

[Omnikron13]

https://goplay.tools/snippet/As2DuKgKzsX

[Omnikron13]

Hashes my username to #63988b:

dlvhdr to #aa8862:

[Omnikron13]

Repo here that I'll probably expand upon somewhat that does just this sort of hash->colour https://github.com/Omnikron13/hash-colour

[Omnikron13]

Considering people may be using colour palettes of their own and want to be all neat and ricey about shit, I suppose I should also add an option that just does a modulus on the hash and pulls from a preset list, aye?