Sparkle skirts is going to be at the expo. They might have the silver there. Or you could try contacting Leah. She might make one for you in silver. But to answer your question, purple.
In regards to sparkle skirts, I got mine in today. I ordered the sparkle light so I could wear my own compression shorts under. I can definitely see the value to ordering the one with the built in shorts. The skirt actually rides up on me. It's not to small or too big. It just doesn't sit right for some reason. I'm thinking of sewing the waistband of my shorts to the waistband of the skirt to hold it in place. I think that will fix the problem. So now I'm wondering if I should tuck my tech shirt in or wear on the outside. What do most people do? Oh and now I'm ditching the Ursula idea. I'm thinking just Halloween colors. Purple skirt, black compression shorts, lime green bondiband (hoping they have this color at the expo as I already ordered 3 and now don't want to wear any of them). Maybe a glow necklace and bracelets. I think I'll just take my entire running wardrobe and what I wear may be a race day/last minute decision.