Trying to gifting Oura as a noob

Not in the space at all. I know what it is, and some of its capabilities.

That being said, the missus wants one, and today being Black Friday, I'd like to snag one for her. What is the ideal way to snag this for a Christmas present without spoiling (or being forced to spoil) the surprise?

From what I'm reading, I can order a v4 in a color as a sizing kit, to complete the order at a later date. However, what I'm really missing is letting her pick the color as well. Am I going to have to make a judgment call on my own here? Or is this something that is enabled during the gifting/sizing option?

TIA to my Oura enthusiasts. Bonus points if you have any tips/suggestions/feedback from a hospital nursing background.