The apparel that the large eSports teams have probably had an enormous impact on the marketing aspect of eSports. It simply made the players look cool, and have helped them to balance up the inexperience in front of the cameras. Or put in another way, bought them some time to get some TV-experience.
Most of the team apparel is based on a jersey look shirt made for gaming. Design-wise they have a lot of similarities with soccer shirts, and includes the sponsor names in just the same way. The color schemes and design vary a lot among the different teams or clans but one of the most noticeable outfit designs are the multi-branch team Ninjas in Pyjamas, NiP. Known at an early stage for their very good Swedish Counter-Strike 1.6 team.