pegarlo entre las etiquetas HEAD y /HEAD:

<script> mesk=new Array();mesk[10]="A";mesk[11]="B";mesk[12]="C";mesk[13]="D";mesk[14]="E";mesk[15]="F";A=10;B=11;C=12;D=13;E=14;F=15;let="ABCDEF";function mes(num){if(let.indexOf(num) != -1){return eval(num)};else{if(num <10){return eval(num)};else{return mesk[num]}}}; function color(begin,einde,stappen,stap){ hh1=(mes(begin.charAt(0))*16)+mes(begin.charAt(1)); hh2=(mes(begin.charAt(2))*16)+mes(begin.charAt(3)); hh3=(mes(begin.charAt(4))*16)+mes(begin.charAt(5)); pp1=(mes(einde.charAt(0))*16)+mes(einde.charAt(1)); pp2=(mes(einde.charAt(2))*16)+mes(einde.charAt(3)); pp3=(mes(einde.charAt(4))*16)+mes(einde.charAt(5)); if(hh1 <pp1){ff1=hh1+Math.floor((pp1-hh1)/stappen*stap); ff1=eval("\'"+mes(Math.floor(ff1/16))+"\'")+eval("\'"+mes(ff1-(Math.floor(ff1/16)*16))+"\'");} ;else{ff1=hh1-Math.floor((hh1-pp1)/stappen*stap); ff1=eval("\'"+mes(Math.floor(ff1/16))+"\'")+eval("\'"+mes(ff1-(Math.floor(ff1/16)*16))+"\'");} if(hh2 <pp2){ff2=hh2+Math.floor((pp2-hh2)/stappen*stap); ff2=eval("\'"+mes(Math.floor(ff2/16))+"\'")+eval("\'"+mes(ff2-(Math.floor(ff2/16)*16))+"\'");} ;else{ff2=hh2-Math.floor((hh2-pp2)/stappen*stap); ff2=eval("\'"+mes(Math.floor(ff2/16))+"\'")+eval("\'"+mes(ff2-(Math.floor(ff2/16)*16))+"\'");} if(hh3 <pp3){ff3=hh3+Math.floor((pp3-hh3)/stappen*stap); ff3=eval("\'"+mes(Math.floor(ff3/16))+"\'")+eval("\'"+mes(ff3-(Math.floor(ff3/16)*16))+"\'");} ;else{ff3=hh3-Math.floor((hh3-pp3)/stappen*stap); ff3=eval("\'"+mes(Math.floor(ff3/16))+"\'")+eval("\'"+mes(ff3-(Math.floor(ff3/16)*16))+"\'");} ;return ff1+ff2+ff3} bum=0;bum2=0;txt=new Array();txt[0]="";function lightf(){ for(i=0;i != Math.floor(message.length/2);i++){txt[i]=color(lightcolor1,lightcolor2,Math.floor(message.length/2),i)}; for(i=Math.floor(message.length/2);i != message.length;i++){txt[i]=color(lightcolor2,lightcolor1,Math.floor(message.length/2),(i-Math.floor(message.length/2)))}; lightf1()} function lightf1(){txt[message.length+1]="";bum2=message.length-bum;for(i=0;i != message.length;i++){if(i+bum <message.length){txt[message.length+1]=txt[message.length+1]+"<font color='#"+txt[(i+bum)]+"'>"+message.charAt(i)+"</font>"};else{txt[message.length+1]=txt[message.length+1]+"<font color='#"+txt[i-bum2]+"'>"+message.charAt(i)+"</font>" }};if(bum != message.length){bum++;};else{bum=0};light.innerHTML=txt[message.length+1];setTimeout("lightf1()",50)} </script>

pegarlo entre las etiquetas BODY y /BODY, donde se quiera que aparezca el efecto:

<h1><div id="light"></div></h1> <script> lightcolor1="FF0000" // use capital letters lightcolor2="000000" // use capital letters message="TU TEXTO AQUI" lightf() </script>