Alright, you gonna have to stick with on this one. The red on the sides are big curved wall'ish fomations out of LR. They come from the back corner, and work their way towards the front of the tank, angling in, and sloping down as they come towards the front of the tank. They really don't touch the side panes too much, or the back wall to much. Imagine them about 8" thick or so. The gray circles are there to help with the idea that the intent is to build those as 'open as possible.' Get the leading curved edge defined, but in the center parts, try for as large openings as possible.
The gray is the back wall, a shallow rock wall. The white center, overflow, is also covered in rock, but as thin as possible. The green wings are massive arches that connect either from the overflow to the back wall, or from the curved formations to the back wall.
If anyone can imagine what I'm trying to get across, I'd be shocked. Though the way I see it, it would honestly look like a slice of the reef.