Also, just to add a little twist to the selections, I'm attaching an image which was entered in a Moodle logo t-shirt contest at moodle.org. It really caught my eye because it says PEOPLE. It feels really friendly and inviting, and also gives the impression that there are many different personalities and interests in the mix. It also has a little bit of "find Waldo" to it.
Does anyone have a new suggestion or variations on the logo selections in the voting booth?
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)
I have a personal dislike of orange, but I don't have another suggestion. It's interesting to look at some ideas on the symbolism and meanings of various colors:
(where orange is "vitality and endurance"; how about some yellow for "intellectual energy")
Here's a site with more extensive descriptions: