CFLib.org – Common Function Library Project

Description:
Takes a hex color in, and returns the closest web safe hexadecimal color. Returns a NULL (empty) string if input hex string is invalid. Thanks to Eric Carlisle (IsWebSafeColor)

Return Values:
Returns a string.

Example:

<CFOUTPUT>
003366, #closestWebSafeColor('003366')#<br>
aabbcc, #closestWebSafeColor('aabbcc')#<br>
112233, #closestWebSafeColor('112233')#<br>
eeffgg, #closestWebSafeColor('eeffgg')#<br>
fffffcc, #closestWebSafeColor('fffffcc')#<br>
##c0c00c, #closestWebSafeColor('##c0c00c')#
</CFOUTPUT>

Parameters:

Full UDF Source:

/**
 * Returns the closest web safe hexadecimal color for a given hexadecimal color.
 * 
 * @param hexInput       (Required)
 * @return Returns a string. 
 * @author Tony Brandner (tony@brandners.com) 
 * @version 1, July 15, 2013 
 */
function closestWebSafeColor(hexInput) {
  var cleanHexInput = replace(hexInput,'##','','ALL');
  var hexOutput = '';
  var i = 0;
  if (Len(ReReplace(cleanHexInput, "[0-9abcdefABCDEF]", "","ALL")) eq 0 and Len(cleanHexInput) eq 6) {
    for (i=1; i lte 5; i=i+2) {
      closestMatch = 51 * Round((InputBaseN(mid(cleanHexInput,i,2),16)/51));
      if (closestMatch eq 0) {
        hexOutput = hexOutput & '00';
    } 
      else {
        hexOutput = hexOutput & FormatBaseN(closestMatch,16);
      }
    }
    return hexOutput;
  } 
  else {
    return 'invalid';
  }
}