Media query breakpoints

As I understand it, the media query breakpoints for Omega, out of the box are:

Narrow: all and (min-width: 740) and (min-device-width: 740px), (max-device-width: 800px) and (min-width: 740px) and (orientation:landscape)
Normal: all and (min-width: 980px) and (min-device-width: 980px), all and (max-device-width: 1024px) and (min-width: 1024px) and (orientation:landscape)
Wide: all and (min-width: 1220px)

I'm attempting to set up a theme for content that will be inserted into a web page via iframe, so the current breakpoints are to wide for my need and I need to alter them to support narrower breakpoints. However, when I even start to test style sheets being loaded correctly, Omega is bypassing the Narrow version and going straight from Normal to Global. In other words if the global page is orange, the narrow page is blue, the normal page is green and the wide page is yellow, when I downsize the browser width to 820px, I'm not getting a blue background, as I think I should. It appears that all stylesheets are being loaded, but the narrow version is avoided.

Am I missing something here?

Secondly, if I want to set narrower widths, is it simply a matter of adjusting the values as follows?

Narrow: all and (min-width: 480) and (min-device-width: 480px), (max-device-width: 800px) and (min-width: 480px) and (orientation:landscape)
Normal: all and (min-width: 640px) and (min-device-width: 640px), all and (max-device-width: 720px) and (min-width: 720px) and (orientation:landscape)
Wide: all and (min-width: 780px)

I do seem to get adjustments appropriately when I do that, but again, I'm not seeing the 'Narrow' style.