I set up the Colorbox plug-in on a test page of this site: http://amatoarchitecture.com/new/oakvale.html
The first three large images are wrapped in an tag with the proper href and class added (copying from the Colorbox demo).
<p>
<a style="display: block; width: 497px; height: 427px;" class="group1" href="images/28oakvale1.jpg" Title="Testing, testing, 123...">
<img class="rsImg" data-rsTmb="images/28oakvale1.jpg" src="images/28oakvale1.jpg" width="514" height="435" />
</a>
</p>
However, when I click the link, no lightbox is launched. Instead, the link just clicks through to the image itself.
I suspect that the two Jquery plug-ins (Colorbox and RoyalSlider) are conflicting. However, I don't know how to tell whether Colorbox is correctly installed either.