将JQuery var发送到php var

I installed OpenCart CMS and wanted to modify some option in the admin panel mainly the look and feel of the template. I also added the jpicker script for color picking. Also i created the css file with the standard php code and it works fine

<?php header("Content-type: text/css; charset: UTF-8"); ?>

<?php 
        $headerColor;
        $menuColor = '#121212';
        $bodyColor = '#fffaaa';

?>

    #header {
        background-color: <?=$headerColor; ?>;
    }

In order to create the color picker view you need to add the id of the div in a script

$(document).ready(function(){
  $('#Expandable').jPicker(
    {
      window:
      {
        expandable: true
      }
    });
 });

And here is the standard code for the html

<div id="Expandable"></div>

I am not very good at JQuery but i know that it can be done either with .ajax or post. What i want to do is send the hex value from the jpicker to a php variable in the css file so it can change the color. Here is the link to jpicker http://www.digitalmagicpro.com/jPicker/. I also found an example

  var colorValue = '#ababab';
  $.post("view/stylesheet/stylesheet-template.css", {var_value: colorValue}, function(data) {
    alert(colorValue);
});

It only sends alert and the colorValue from the variable, but i still don't know how to send the colorValue to php from the jpicker.

Thanks

function sendToPhp(jCell){
$.ajax({
    url: "php/ajax.php",
    data: {cell: jCell, queryNr: "0"},
    type: "POST",
    async: false,
    success: function(data){ callback(data); }
    });
}

now cell and queryNr is sent to php

if u do a switch case function depending on query nr you can access multiple functions in php this way

for the comment:

function sendToPhp(jCell, phpUrl){
$.ajax({
    url: phpUrl,
    data: {cell: jCell, queryNr: "0"},
    type: "POST",
    async: false,
    success: function(data){ callback(data); }
    });
}

now you can hand over a specific path by calling the function like:

sendToPhp("VAR YOU WANT TO SEND TO PHP", "php/ajax.php"); // or any other path