all elements in class show as even - html

Question

On my webpage there are DIV's that are created dynamically with the class of jOUT.
I want to change the color of every other iteration of the class.
I'm trying to do it this way:
.jOUT:nth-child(even){
background:#eeefff;
}
.jOUT:nth-child(odd){
background:#cccffe;
}
My HTML is as follows:
<div id="outData">
<input type="hidden" name="outDivider" value="-------">
<div class="jOUT isOpaque">
<!-- ... -->
</div>
<input type="hidden" name="outDivider" value="-------">
<div class="jOUT isOpaque">
<!-- ... -->
</div>
<input type="hidden" name="outDivider" value="-------">
<div class="jOUT">
<!-- ... -->
</div>
</div>
Full HTML here
But it's not working. What's really weird is that using the console in Chrome, when I select each jOUT, it shows ALL of them as having the "even" attribute.
I thought for sure that I had invalid CSS or HTML but I can't find it. It has to be something I'm doing, but what? I guess what I'm asking for is an idea for a place to start looking for the problem. I've verified the CSS using w3c CSS verification, and the HTML using HTML Tidy.

Answer 1

Your current CSS is working as it should, because you're targeting ALL children (including input); which means, in this scenario, all your div.jOUT are even - you should rather use :nth-of-type, which will only target instances of div.jOUT ...
.jOUT:nth-of-type(even){
background:#eeefff;
}
.jOUT:nth-of-type(odd){
background:#cccffe;
}
DEMO fiddle

Answer 2

This would work here:
.jOUT:nth-child(4n){
background:#eeefff;
}
More on that
This is somewhat fragile, though. A better approach is to add an alternative style class on those elements, possibly via your server-side app.

Answer 3

Your input[name="outDivider"] elements are in the way, thus making every jOUT element even. Here's a working pen where I took them out and made the selector work properly. I also changed the colors, so it's easier to see.
Edit: #isherwood beat me to it, but if this input[name="outDivider"] elements are absolutely necessary, his solution works best!