Logo Designer Blog gives us a refresher course in color theory, listing the connotations of each color, and how some popular logos use the color “rules”:

• Red evokes aggressiveness, passion, strength and vitality
• Pink evokes femininity, innocence, softness and health.
• Orange evokes fun, cheeriness and warm exuberance.
• Yellow evokes positivity, sunshine and cowardice.
• Green evokes tranquility, health and freshness.
• Blue evokes authority, dignity, security and faithfulness.
• Purple evokes sophistication, spirituality, costliness, royalty and mystery.
• Brown evokes utility, earthiness, woodsy-ness and subtle richness.
• White evokes purity, truthfulness, being contemporary and refined.
• Gray evokes somberness, authority, practicality and a corporate mentality.
• Black evokes seriousness, distinctiveness, boldness and being classic.

Via Logo Designer Blog.