Failure to do this will mean that you are preventing yourself from reaching a whole audience that you should be able to work with and who should be able to help promote your business. Likewise you should offer your custom clothing in a variety of colours. You might have chosen red or black as the background colour of the t-shirt because you think it looks best, or because you think that it best reflects your business. However by giving your wearers the opportunity to choose their own clothes, you thereby open it up to more people again (some people just don’t look good in certain colours). It also means that they can wear them in more scenarios as they will go with multiple colours of other items. As mentioned you will want to choose whether to provide custom polo shirts, custom sweatshirts or embroidered hats; however bear in mind that you would do even better to produce multiple types of custom clothing meaning that you can give them away at different events and that people will be able to wear them in more scenarios.