Color Tester 2 in HTML , CSS , JS

<html>
<head>
<title>Color Tester</title>
<script>
function change(){
function abcdef(hh){
if(hh==10){
hh="A";}
else if(hh==11){
hh="B";}
else if(hh==12){
hh="C";}
else if(hh==13){
hh="D";}
else if(hh==14){
hh="E";}
else if(hh==15){
hh="F";}
else if(hh==16){
hh="F";}
return hh;}
x="#";
r1=document.getElementById("red1").value/6.25;
r2=document.getElementById("red2").value/6.25;
g1=document.getElementById("green1").value/6.25;
g2=document.getElementById("green2").value/6.25;
b1=document.getElementById("blue1").value/6.25;
b2=document.getElementById("blue2").value/6.25;
rr1=r1-r1%1;
rr2=r2-r2%1;
gg1=g1-g1%1;
gg2=g2-g2%1;
bb1=b1-b1%1;
bb2=b2-b2%1;
rr1=abcdef(rr1);
rr2=abcdef(rr2);
gg1=abcdef(gg1);
gg2=abcdef(gg2);
bb1=abcdef(bb1);
bb2=abcdef(bb2);
HexColor=x.concat(rr1,rr2,gg1,gg2,bb1,bb2);
document.getElementById("ttt").value=HexColor;
document.body.style.background=HexColor;}
</script>
<style>
#ss{border:2px solid #000000;
position:absolute;
top:25%;
left:25%;
margin:auto;
text-align:center;
background-color:#BBBBBB;}
</style>
</head>
<body>
<br/><br/>
<div id="ss">
<br/><p>#123456</p><br/>
<form oninput="change()">
<input type="range" value="50" id="red1"/>1 red<br/><br/>
<input type="range" value="50" id="red2"/>2 red<br/><br/>
<input type="range" value="50" id="green1"/>3 green<br/><br/>
<input type="range" value="50" id="green2"/>4 green<br/><br/>
<input type="range" value="50" id="blue1"/>5 blue<br/><br/>
<input type="range" value="50" id="blue2"/>6 blue<br/><br/>
<input type="text" id="ttt"/><br/>
</form>
</div>
</body>
</html>