>>4429242...well now that's a good question, the real why for the blue polo shirt i don't know for sure, i know it was in vogue until the mid-00's because i was part of it but the tan vest is easy to answer as it is the standard for pros: Pockets for rolls, colour filters, and the lower ones for a couple of primes.
The tan of it i suppose is cargo canvas or some form of tough nylon textiles resembling cargo which are considerably durable aka work-grade, it was the heyday's hipster photocentric backpack equivalent or the "moneymaker" double sling from a decade ago.
Back then you knew for sure he was a photographer, nowadays they look like students with an oversized backpack and a decade older. The 2010's had a strange combination of old ways with new stuff.