People have been absolutely obsessed with Starbucks' color-changing cold drink tumblers ever since they launched last year. To be fair, people are always obsessed with Starbucks cups, but there's just some sort of joy about watching your cold drink interact with the cup like a little science experiment.
Since they're so popular, they sell out pretty quickly, which can be so upsetting to those who have waited a whole year for their release.
While they may not have the Starbucks Siren plastered on the front, Costco is selling a large pack of color-changing colors so you always have one ready to go.