I was just thinking about Egyptian games the other day. The Celtic knot throws out the historical theming, but I like the colour palette, its not over gaudy and using contrasts as you have areas with less saturation brings the coloured areas out more.
You might want to watch the art film Lucifer rising by Kenneth Anger to get you in the mood. (try VeeHd for a higher res copy)
My suggestion - A pack like the first Tron film. So we are talking electronic world with glowing grids.
Ill contribute skyboxes if this is selected.
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Here is an even better idea, a segment pack, with segments of all different shapes,
no 100x100x10 flat wall segments.
One of my pet hates being an old school BSP level designer back in the day is we made levels with interesting brushes. FPSc users make box rooms with hundreds of squares blocks that waste polys and resources, there is no wonder fpsc runs like sludge, its wasteful, flat squares all over the place, hundreds of them, if you are going to use a program that is wasteful in terms of building method all be it fast for design (note cube engine builds things with blocks but then it merges them, ie two blocks side by side, get merged into one block) anyway, fpsc is wasteful in how it builds levels, so at least use segments of different thickness or shape, that way you use all the polys on screen.
Ill also say, I have never seen a good level designer amongst every fpsc user I have ever seen. Note I said level designer, not level decorator, take all decorative entities out of your level leaving just the 'actual' game geometry, thats the actual 'level design'. I have never seen any good level geometry, the vertical axis also doesn't exists, what happens is users build boxes out of segments, then fill them with entity 'objects', pots pans, beds, ornaments, you name it, actual level design, you never see any. Part of the blame is reliance of decorative entities, and a lack of segment shapes.
So the best pack to make would be a pack of interestingly shaped segments.