I took my cadet to a store that specializes in sneakers. He had to run on a treadmill and they observed and then made recommendations based on how he ran.
Expect to spend some serious coin on footwear (sneakers/boots/shoes) and socks.
It'll be worth every penny.
Both my DS & DD are cross country & distance track runners for their high school and I can tell you we need to replace their training running shoes 3-4 times a year (in addition to their XC spikes & track spikes). We have taken them to our local running store many times to determine best fit/function. Luckily for us, they have both found pairs that they love and suit their individual running styles so they tend to repurchase the same style over & over now. That allows us to look online and/or stock up when we see them on sale. If they want to change shoe styles/brand we always head back to the running store.IF the letter does not give color-guidance, then there is no requirement about the color. However, if you show up in bright red sneakers, it will be extra easy for you Team Leader to spot you in a group. I'll let you decide if that is a positive or a negative.
The sneakers should be relatively new so that they still have a lot of life in them. You will run quite a lot at WP and you may wear them out faster than you are accustomed to (unless you are a runner - then you understand that sneakers have a fairly short lifespan). My son brought fairly new running sneakers to beast and by the end of the fall semester, they were completely worn out. And I mean completely dead! If you've been running in your sneakers for a few months before beast, then they may not last the semester.