Updated fiddle showing how to do it: http://jsfiddle.net/ux4DD/181/
It should be noted that selects are notoriously unreliable when it comes to styling cross-browser so your styling may not appear consistently across all browsers/version.
select {
height:50px;
background-color: #dcdcdc;
}
If you only want one select to have a specific background color/style use a class to define it e.g.
<select class="my-select-class">
<option>2</option>
</select>
.my-select-class {
background-color: #dcdcdc;
}
It's not recommended to use inline styles on your web pages as this makes them a nightmare to maintain down the line.
Stick to external stylesheets.