Keeping the logo simple is a sensible advice as logos are needed to be versatile. However, this simplicity restricts the logo to three colors. Designers say that using more than three colors can be overwhelming and can distract the audience. But there are brands that choose to use more than three colors and still manage to be successful. Windows is a good example for having a successful logo with more than three colors. The point is that a design is subjective in its core. A cartoon logo should not be designed while following the rules for an air plane logo and vice versa.