That would work alright.. red and light blue go together fine.. just look at GW's kislevite colour scheme. As long as there's some sort of contrast with either the colour intensity (bright/dull) or the tone (dark/light) it works.
Yeah, the Kislev scheme is quite lovely. They use a lighter grey/blue and a nice vibrant red.
I think grey and white are fine, just look at anything made by apple.
The electronics industry is one of those places where clean and sterile is an ideal look. But you'll also note that apple loves pretty candy-like colors, especially on thier I-macs and I-pods.
A combination of 2 different dark colours would look a lot worse... altdorf and hochland are not good schemes.
Hochland is a good scheme if done right. However it's difficult to do right. My first empire troops were painted in a red/green scheme and they looked godawful. However, if you look in the old empire book under the "state colors" section you'll see a rather nice looking Hochland handgunner. His green is dark and his red is bright which gives him a nice contrast.
The Altdorf trooper doesn't look as good though because he doesn't have enough contrast between the red and blue. This is why, on my Altdorfers, I'm going with blue and white as the primary colors, with red as an accent color for ribbons and tassles and such.
If you want a good example of a dark color scheme that doesn't work particularly well, the Sylvanian colors (purple and red) are probably the best example. I also think they're a bit too close on the color wheel to stand out from each other.
It's also worth noting that the old "State Colors" section with painted miniatures is much better than in the new book where you've got coloring-book pictures of the troopers. It gives you a better idea of how to actually paint to the minis to get the color schemes to work.
And, wonder of wonders, there are actually some Wissenlanders there in the corner that don't look half bad. It helps that the old spearman uniforms have puffy sleeves to add some texture and shadow to the model. This'll be hardfer to pull off on the new models, with thier larger flat areas. I still think it's a poor scheme, but the Eavy Metal team did manage to make it look respectable.