What makes a good logo. Part 1.
Being a logo is tough work. You have to stand out amongst the crowd: business cards, signs, posters, ads, websites, et cetera. And, you have to take a lot of abuse: being stretched and squahed and resized. So, one of the ways to judge a succesful logo is if it translates well into different colors. (See examples below.) If a logo looks good in various colors, it's a sign that the logo has an aesthetic integrity that essentially acts as a frame against the hustle and bustle of the outside world.