Hex-to-CMYK Conversion

JavaScript FAQ | JavaScript Colors FAQ

Question: How do I convert a hex color string (e.g. "FFFFCC") to CMYK values of the same color?

Answer: The CMYK (Cyan, Magenta, Yellow, blacK) color model is widely used in printed media. Below is a simple hex-to-CMYK color converter function. It uses, as its initial step, the hex-to-RGB conversion. Try it yourself:

function hexToCMYK (hex) {
 var computedC = 0;
 var computedM = 0;
 var computedY = 0;
 var computedK = 0;

 hex = (hex.charAt(0)=="#") ? hex.substring(1,7) : hex;

 if (hex.length != 6) {
  alert ('Invalid length of the input hex value!');   
  return; 
 }
 if (/[0-9a-f]{6}/i.test(hex) != true) {
  alert ('Invalid digits in the input hex value!');
  return; 
 }

 var r = parseInt(hex.substring(0,2),16); 
 var g = parseInt(hex.substring(2,4),16); 
 var b = parseInt(hex.substring(4,6),16); 

 // BLACK
 if (r==0 && g==0 && b==0) {
  computedK = 1;
  return [0,0,0,1];
 }

 computedC = 1 - (r/255);
 computedM = 1 - (g/255);
 computedY = 1 - (b/255);

 var minCMY = Math.min(computedC,Math.min(computedM,computedY));

 computedC = (computedC - minCMY) / (1 - minCMY) ;
 computedM = (computedM - minCMY) / (1 - minCMY) ;
 computedY = (computedY - minCMY) / (1 - minCMY) ;
 computedK = minCMY;

 return [computedC,computedM,computedY,computedK];
}

See also:

JavaScript Colors FAQ Hex to RGB color converter RGB to Hex color converter RGB to CMYK color converter   RGB to HSV color converter

Changing the page background color Changing the color of HTML elements Predefined color names (alphabetical list) Applying another stylesheet to my page Changing the mouse cursor style