Generate a color palette between two colors. Returns hex css codes.

gradient.generator.php

<?php
 /** Thanks to http://www.herethere.net/~samson/php/color_gradient/ 
  Usage : 
  *  print_r(_generateGradients('000000','FFFFFF',16));creates 16 nuances between white and black, returns hex css
 print_r(_generateGradients('#FF0000','#800080'));
 */

function _generateGradientsInterpolate($pBegin, $pEnd, $pStep, $pMax) {
		    if ($pBegin < $pEnd) {
		      return (($pEnd - $pBegin) * ($pStep / $pMax)) + $pBegin;
		    } else {
		      return (($pBegin - $pEnd) * (1 - ($pStep / $pMax))) + $pEnd;
		    }
		  }

 function _generateGradients($theColorBegin=0x000000,$theColorEnd=0xffffff,$theNumSteps=10)
 {
 	//transform to hex, and get rid of # if exists
 	$theColorBegin = hexdec(str_replace('#','',$theColorBegin));
 	$theColorEnd = hexdec(str_replace('#','',$theColorEnd));
 	
 	//failsafe color codes
		$theColorBegin = (($theColorBegin >= 0x000000) && ($theColorBegin <= 0xffffff)) ? $theColorBegin : 0x000000;
		$theColorEnd = (($theColorEnd >= 0x000000) && ($theColorEnd <= 0xffffff)) ? $theColorEnd : 0xffffff;
		$theNumSteps = (($theNumSteps > 0) && ($theNumSteps < 256)) ? $theNumSteps : 16;	
 
		$theR0 = ($theColorBegin & 0xff0000) >> 16;
		$theG0 = ($theColorBegin & 0x00ff00) >> 8;
		$theB0 = ($theColorBegin & 0x0000ff) >> 0;
		
		$theR1 = ($theColorEnd & 0xff0000) >> 16;
		$theG1 = ($theColorEnd & 0x00ff00) >> 8;
		$theB1 = ($theColorEnd & 0x0000ff) >> 0;
		 
		 $result = array();
		 
			for ($i = 0; $i <= $theNumSteps; $i++) {
				$theR = $this->_generateGradientsInterpolate($theR0, $theR1, $i, $theNumSteps);
				$theG = $this->_generateGradientsInterpolate($theG0, $theG1, $i, $theNumSteps);
				$theB = $this->_generateGradientsInterpolate($theB0, $theB1, $i, $theNumSteps);
				
				$theVal = ((($theR << 8) | $theG) << 8) | $theB;
				$result[] = sprintf("#%06X",$theVal);//strtoupper(str_pad(dechex($theVal),6,'0'))
			}
		return $result;
 }//end _generateGradients