Liveries around the world are the calling cards for hundreds of different airlines. For some they are the passengers only interaction with the brand image of the airline, so as they park up at the gates of airports globally, they need to be able to communicate the values and concepts that each airline brand stands for.
TheDesignAir has done a great job categorizing carriers with what they represent—from low cost carriers to legacy flag ones—and how that translates with the choice of livery for their planes.
I'd love to hear their thoughts on the new A380 livery that Etihad has now made official. I find it strikingly dashing for a flag carrier (many, including TheDesignAir in its otherwise great article here, mistake Emirates as the national UAE airline, which it is not).