Here's a list of some of my favorite places to look for a winter or color guard costume. They're in no particular order but I've added a quick blurb about each to help you find what you're looking for. I have had good experiences with all of these sites and would recommend any of them. Choosing a costume for your guard depends on budget, show design, and style! Good luck!
The Band Hall is probably the best place to go for traditional guard costumes. They will also work with you to create custom designs. Several big name drum corps and winter guards use this company for their costume needs.
A Wish Come True is a newer company that has really grown and offers a wide variety of costumes for guard and dance. They have some very unique fabrics you can choose from when personalizing your order.
Discount Dance Supply has basics, tops, bottoms, and some dresses all at a great price. These will cost quite a bit less than typical guard costumes.
Fred J. Miller is another big name with typical guard costumes and big name clients.
McCormick's is one of my favorite companies to order from because it's a little smaller. You get great customer service and fast delivery. They only have a few costumes available in stock, but they will work with you individually to create custom designs.
Guard Closet is a website where you can buy used equipment, flags, and costumes. Color guards can post items for sale on this site and they are often at a steep discount but still in good condition.
Style Plus offers several costumes in stock which is good if you wait until the last minute to place your order! They also have some very fun and modern fabrics to choose from, even if they don't have the largest variety.
Dancewear Solutions sells mostly dance basics and practice wear but has some gorgeous performance pieces to choose from. They have low prices and excellent shipping costs.
THANKS FOR READING! For more tips and fun stuff about the marching arts
OR if you are interested in custom Winter Guard show design, drill, and
choreography or Marching Band drill and Color Guard choreography, check
out my website at marchandspin.com.