Bradley from the Adafruit Community spotted this and shared it with us: Tail Lights: LED Wearable Safety Indicators for Your Next Horse Ride. I particularly appreciated the photo showing options they considered before the locked in on the bright RGB LED strips they are using here. A TRON horse costume might win you some points in the barn and the yard, but be less safe an indicator on the side of the highway:

On a cool November evening Sami, our founder, and her friend were riding both of Sami’s horses back to the barn.  Despite living in an equestrian community and using reflectors, Sami’s horse and her friend were struck by a car.  It was a hit and run.

Although her friend was thankfully unharmed, her horse Afar was not.  Thousands of dollars later in veterinarian expenses Sami made it her mission to design and develop the most advanced safety lighting system for horses the world has ever seen.

That is how Tail Lights, the product, was born. She wanted a bright, versatile, tough, yet beautiful way to make her and any others horses presence on the road known.  

…The Tail Lights family hope that you love this product as much as we do. This product is made by horse people for horse people.

Read more.