Kim Kardashian mightve gotten a little too into the Halloween spirit this year.

The Keeping Up With the Kardashians reality star revealed Sunday that she stopped by Trace Ellis Ross 50th birthday festivities over the weekend, but didnt realize until she got there that it wasnt a Halloween-themed celebration.

That time I showed to a birthday dinner in full costume when it wasnt a costume party! Kardashian wrote on Instagram alongside a photo of her with Ross. Happy Birthday to the most beautiful kind soul @traceeellisross.

The Skims founder was wearing a hyperrealistic Mystique costume from the X-Men series skin-tight bodysuit, red hair, yellow eye contacts and a whole lot of bright blue paint. Ross was dressed in a glamorous red get-up with diamonds.