nivyed

The article suggests using a named return value `err` to allow the return value of `Close` to be be propagated - unless doing so would overwrite an earlier error:

    defer func() {
        cerr := f.Close()
        if err == nil {
            err = cerr
        }
    }()

Wouldn't it be better to use `errors.Join` in this scenario? Then if both `err` and `cerr` are non-nil, the function will return both errors (and if both are `nil`, it will return `nil`):

    defer func() {
        cerr := f.Close()
        err = errors.Join(err, cerr)
    }()

Does anyone know why HUSL is based on CIELUV rather than CIELAB?

It seems that, although CIELUV and CIELAB were considered equally good when adopted in 1976, CIELAB has generally been preferred more recently (e.g. for the 1994 and 2000 "Delta E" formulae [1]).

[1] https://en.wikipedia.org/wiki/Color_difference#Delta_E