func randomRGB(uid int) color.RGBA {
	b := binary.BigEndian.AppendUint64(nil, uint64(uid))
	h := sha256.Sum256(b)
	return color.RGBA{h[0], h[1], h[2], 255}
}

That took me under three minutes and half of that was remembering that RGBA is in the color package, not the image package, and uint-to-bits is in the binary package, not the math package. I have found chatgpt useful when I was working in a different language. But trying to get chatgpt or copilot to write tests or documentation for me (the kind of work that bores me to death), doing the prompt engineering to get it to spit out something useful was more work than just writing the tests/documentation myself. Except for the time when I needed to write about 100 tests that were all nearly the same. In that case, using chatgpt was worth it.