convert a string to hexcode
<p>I want to convert a string to a colorhexcode in JavaScript or php. </p>

<p>Is there a way to do that? The strings look like <code>dfc6d9ff5a1d394e</code> or 
<code>2b514f260aad317a</code>.
The background is that these are unique ids and I want to convert them to unique colours...</p>
