Re: colour bars at top and bottom...
I love the Celtic knot background!
The only suggestion I have is you might want to consider changing the link hover color on the navigation text at the top of the page (Home | login) because it disappears against the graphic. And maybe increase the size of those links a little so they stand out more against the graphic. They get a little lost.
I love the Celtic font in your header -- I've used a similar one for another site I created. That's a very nice, clean logo and color combo you've used with the background.
I'm not normally a fan of "busy" background patterns, but the colors and the pattern of yours works.
Good job!
Lesli in SW Florida ~ writer, teacher, and dodging hurricanes!