@Override
    public String toString() {
        return "{C: " + c + ", M: " + m + ", Y: " + y + ", K: " + k + "}";
    }
Constructs a new instance.

@param c cyan.
@param m magenta.
@param y yellow.
@param k key.
src/main/java/org/apache/commons/imaging/color/ColorCmyk.java