Senescence is a dark olive green base with copper shimmer and subtle holo sparkle. I wasn't sure what free polish I was going to get but I'm happy to say that I'm completely thrilled with this one! It's such a beautiful color. The shimmer is amazing. It's also unique to my collection. Formula wise, I was impressed. It was easy to apply and I only needed two coats, plus a coat of top coat.
This is the first polish I've worn from my Windestine order and I'm completely happy with it and the brand. It doesn't look like Senescence is being sold in the Etsy shop. It's probably a discontinued color from a previous collection, but who knows, you might get lucky and end up with it in your order!
Windestine is sold here for $8 a bottle. Minis are also available for $3.