Equestrian fashion question.

So once upon a time a was a bit of a fashionista. I knew what to wear for every occasion and I stayed current with the trends. I was even going to school for fashion marketing and management. Well then I moved to a farm and forgot everything I ever knew about what to wear. As far as what to wear on horseback it's always been to wear what is comfortable as I've never really been in the show ring.
My question is what is fashionable in the show ring? For the dressage schooling shows at my last barn we could wear either a plain polo, clean breeches in whatever color we had, tall boots or paddock boots and half chaps OR we could wear a black show coat, stock tie, white breeches, and tall boots if we had them. The first show I wore a black polo and my slightly off white breeches (that are apparently magic breeches because I bought them when I lived in Sweden over 13 years ago and they still fit even though I am NOT the same size!). The second show I had been given a full show ensemble and wore that. If I were to show dressage again I would wear that obviously. But what is fashionable when you aren't showing dressage?
I was going through my show clothes the other day and found a fabulous light grey with pink piping show coat by Equine Couture that I am I love with. When on earth would I wear it? I'm sure it's not even fashionable anymore, but it sure is pretty... Can I wear it when showing a walk trot class? For jumping classes? What are people wearing these days? Are dark colors like black and navy blue more fashionable than lighter colors? Obviously I am putting the cart way before the horse here as I don't even know if I am gonna show or have a horse I can show...I'm just sort of wondering what to wear IF I do make it to the show ring this year...