Just to address some color issues, it is true that there is plenty of research regarding the psychological effects of color and many cultural meanings implied by its use. From my experience, a graphic designer will take a more intuitive approach to color selection. One thing is true, color is a very subjective topic, and different people prefer different ones. I tend to consider the "visual effect" of how different colors work together as a key factor when choosing between this color or that.
For the initial designs I chose a "monochromatic" approach, which is generally using only one color with variations of light and dark. The revised design I just posted to kates comments above, now uses a little "complimentary contrast" which as you can tell is a more intense.
I declared orange the "color of champions" for reasons which now escape me, but the fact is that it really sings when surrounded by a bunch of blue! (It's "compliment" or opposite in the color wheel)