Yes, the page actually needs to refresh, so you can't simply use an anchor link to do this. This will present you with the problem that you may find it difficult to determine the "current" page in order to create a link to it. One way just using pure HTML is to make a mini form with a blank URL, and a hidden form field with a value in it. This should be guaranteed to go back to the same page that it came from, and it's easy to check for the form field value in Chameleon:

if (JRequest::getVar("myformfieldname") == "myvalue") return true;

... then that triggers the SUCCEED action in that rule. Use the code above *instead* of detecting the string in the URL.

A very basic form would be:

<form action="" method="post">
<input type="hidden" name="myformfieldname" value="myvalue" />
<input type="select" value="High contrast version">
</form>

Or with a clickable link:

<form action="" id="switcher" method="post">
<input type="hidden" name="myformfieldname" value="myvalue" />
<a href="javascript:void(1);" onclick="javascript:document.getElementById('switcher').submit()">High contrast version</a>
</form>


Hope this helps,
Stephen

Yes, sounds like a good plan.