A new feature in the Hidrate app - Glow Studio lets you combine any two colors to create custom glows to match your style, the season or even your favorite team. Glow Studio only works for the HidrateSpark STEEL bottles, and can be purchased for $4.99 in the app under the Bottles tab. Please note, the $4.99 price is valid for the US, it may be slightly different in other regions.
To open Glow Studio within the Hidrate app, go to the Bottles tab - Glow Studio. That will take you to the page where you can either purchase the feature or start using it, once you've purchased it. If you try to start using Glow Studio before you purchase it you won’t be able to save a glow, the save button will be replaced with a purchase button until you make a purchase.