impl Color {
    // Constructor for CMYK model
    pub fn from_cmyk(c: f64, m: f64, y: f64, k: f64) -> Color {
        if !Self::is_valid_ratio(c) {
            panic!("Invalid Cyan value {} in CMYK model", c);
        }

        if !Self::is_valid_ratio(m) {
            panic!("Invalid Magenta value {} in CMYK model", m);
        }

        if !Self::is_valid_ratio(y) {
            panic!("Invalid Yellow value {} in CMYK model", y);
        }

        if !Self::is_valid_ratio(k) {
            panic!("Invalid Black value {} in CMYK model", k);
        }

        Color::CMYK{ c: c, m: m, y: y, k: k }
    }
}

impl Color {
    // Private class method used to validate ratio value
    fn is_valid_ratio(n: f64) -> bool {
        0.0 <= n && n <= 1.0
    }
}