What type of clothes do Buddhist people wear and why?

Most people who's religion is Buddhism, have baggy clothes in many different colours & patterns

Answer:

There is no Buddhist "uniform". Buddhists dress in a manner consistent with the norms of the location in which they live. In America this might be jeans and hoodies, in Scotland even kilts and at nudist camps nothing at all. Assuming that there is a Buddhist uniform is like thinking that all Christians wear black suits with clerical collars.