The biggest lesson is that color blocking isn't an excuse to pull random, colorful garments out of your closet. "I don't do more than three colors” Don't go overboard or try too hard. When they get into the four and five bright colors, you start to look like a 1980s video game, you start to look almost clownish If you want to stand out in a crowd, people are going to see you right away. You'll probably get lots of compliments if you do it correctly.
For an adventurous fashionista, colorblocking allows you to show your fashion skills, especially when it comes to pulling together colorful separates, new or ones you already own. If you're a colorblock newbie, stick to color blocking a blouse and a jacket… sooner your combination skills will develop once you take the right first step ;)