Tremont template, light/dark logo issue

Site URL: http://www.harborpoint.com

Hello,

Putting the finishing touches on a Tremont site that uses a white logo on the home page, and a darker logo on every other page. 

I've used the solution that was previously posted and I can get the two logos to appear.

<script>
Y.on('domready', function(){
 Y.one("#siteHeader img").setAttribute("src","https://static1.squarespace.com/static/whitelogo.png");
});
</script>

The problem now is that if I go to the site using the site URL, only the white logo appears on all the inside pages. If I go to the site using a URL to one of the inside pages and then click to the homepage, the logo is the darker version. Basically, the way I enter the site seems to dictate the logo appearance for the length of the session. This issue does not happen in the CMS test (it works as anticipated there) - only on the live site.

Any help with this would be appreciated. Thank you!