Well....not as a good example for what you are looking to do (I would stick with the roll-overs, and just have the color "s*******" as individually linked squares to a larger 'replacement' image with the frame added).....but in this example, I have a calendar linked via iFrame to the body of the page since it is a web application that resides elsewhere. I used an iFrame primarily to "mask" the bottom area of the calendar, thus preventing Visitors to 'Logon' and monkey with it ...... (keeps it from being trashed).
>>> www.HerodsIslandTours.com/island_calendar.html


Which brings me to another important tip regarding iFrames: when creating your pages that will present in an iFrame, be sure to register everything as close to the top of the page as possible, as the iFrame will present the WHOLE page it reads from the top-left corner outward....so if your "framed picture" is the only thing on that page, be sure to position it TOP - LEFT on the page, so you can then "re-size" the area of the iFrame to present appropriately!