✅ Hex color converter breaks on 3-digit and 4-digit values

public static Color ParseHexColor(this string input)
{
    var hex = input.Trim('#');
    if (!int.TryParse(hex, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var num))
    {
        throw new ArgumentException("Not a valid hexadecimal number", nameof(input));
    }
    
    return hex.Length switch
    {
        3 => Color.FromArgb(((num >> 8) & 0xF) * 0xFF / 0xF, ((num >> 4) & 0xF) * 0xFF / 0xF, (num & 0xF) * 0xFF / 0xF),
        4 => Color.FromArgb(((num >> 12) & 0xF) * 0xFF / 0xF,((num >> 8) & 0xF) * 0xFF / 0xF, ((num >> 4) & 0xF) * 0xFF / 0xF, (num & 0xF) * 0xFF / 0xF),
        6 => Color.FromArgb((num >> 16) & 0xFF, (num >> 8) & 0xFF, num & 0xFF),
        8 => Color.FromArgb((num >> 24) & 0xFF, (num >> 16) & 0xFF, (num >> 8) & 0xFF, num & 0xFF),
        _ => throw new ArgumentException("Unknown format", nameof(input))
    };
}