Set background colour of select to selected option in JQuery

Replace the "each" with "change"

$('select[id$=-status][id^=id_item-]').change(
    function (){
        var color = $('option:selected',this).css('background-color');
        $(this).css('background-color',color);
    }
).change();

This works in Chrome.

Also see: http://docs.djangoproject.com/en/dev/ref/contrib/admin/#modeladmin-media-definitions

Custom css in django admin is supported.

And I believe that the correct css attribute is: 'background-color'. backgroundColor is javascript and should be used like this: $(this).css({backgroundColor:color}); But it seems to work anyway so no biggie.

EDIT:

If you want to init the script on page load you can just add .change() behind. See code.

I also tested this in firefox and I also see this strange behavior (blue, wth blue?).

Another EDIT:

Ok, so here is a quick fix for firefox:

$('select[id$=-status][id^=id_item-]').children().each(function (){
    if($(this).val() == 0){
        $(this).attr('style', 'background-color:white;');
    }
    if($(this).val() == 1){
        $(this).attr('style', 'background-color:green;');
    }
    if($(this).val() == 2){
        $(this).attr('style', 'background-color:red;');
    }
    if($(this).val() == 3){
        $(this).attr('style', 'background-color:orange;');
    }
});

$('select[id$=-status][id^=id_item-]').change(function (){
    var style = $(this).find('option:selected').attr('style');
    $(this).attr('style', style);
}).change();

Last EDIT:

You could even to this if you're using css:

<style>
    select option,
    select {
        background-color:white;
    }

    select option[value="1"],
    select.o1
    {
        background-color:green;
    }

    select option[value="2"],
    select.o2
    {
        background-color:red;
    }

    select option[value="3"],
    select.o3
    {
        background-color:orange;
    }
</style>

<script>    
    $('select[id$=-status][id^=id_item-]').change(function (){
        var color = $(this).find('option:selected').val();

        $(this).removeClass('o1 o2 o3').addClass('o' + $(this).find('option:selected').val());
    }).change();
</script>

Yet another edit:

I came across this and saw that I could make it shorter so I did just for fun:

$('select[id$=-status][id^=id_item-]').children().each(function() {    
    var colors = ['white', 'green', 'red', 'orange'];
    $(this).attr('style', 'background-color:' + colors[$(this).val()] + ';');
});
$('select[id$=-status][id^=id_item-]').change(function() {
    $(this).attr('style', $(this).find('option:selected').attr('style'));
}).change();

$("select[id$=-status][id^=id_item-]").change(function (){
    var style = $(this).find('option:selected').attr('style');
    $(this).attr('style', style);
    $("select[id$=-status][id^=id_item-] option:selected").each(function () {
            $(this).attr('style', style);
          });
}).trigger('change');

Add style to you HTML code, use trigger don't forget to load this in your $(document).ready(function(){} Also don't forget to put this code after populating your Select box from the DB

I like @Arnar Yngvason's answer but I'll add this to the mix. This solution uses CSS classes so the styles can be easily changed without breaking the rest of the code.

Html

<select>
    <option class="Red">Red</option>
    <option class="Blue">Blue</option>
    <option class="Green">Green</option>
    <option class="Yellow">Yellow</option>
</select>
<div id="output"></div>

CSS

.Red{background-color:#ff0000;}
.Blue{background-color:#0000ff;}
.Green{background-color:#00ff00;}
.Yellow{background-color:#ffff00;}

JavaScript

$("select").change(function(){
    $(this).removeClass($(this).attr('class'))
           .addClass($(":selected",this).attr('class')); 
    /*If you want to keep some classes just add them back here*/
    //Optional: $(this).addClass("Classes that should always be on the select");

});

 $("select").change(function() {
   $(this).removeClass($(this).attr('class'))
     .addClass($(":selected", this).attr('class'));
   /*If you want to keep some classes just add them back here*/
   //Optional: $(this).addClass("Classes that should always be on the select");

 });

    .Red {
      background-color: #ff0000;
    }
    .Blue {
      background-color: #0000ff;
    }
    .Green {
      background-color: #00ff00;
    }
    .Yellow {
      background-color: #ffff00;
    }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select>
  <option class="Red">Red</option>
  <option class="Blue">Blue</option>
  <option class="Green">Green</option>
  <option class="Yellow">Yellow</option>
</select>
<div id="output"></div>

JSFiddle

I've tested this on FireFox 31, IE 11 and Chrome 37