Apple TV 4K calibration question

[Blu-man08]

Does the Calibration feature on the latest iOS version adjust the video settings of your TV, or does it simply adjust some hidden settings within the Apple TV 4K itself? I have performed the iOS calibration on my Vizio, and I presume the video image should reflect that which natively shows on my iPhone 13. I will have to double check switching between disc and Movies App on the ATV4K after work, but last evening I was watching Dracula (Lugosi) on a physical 4K disc, and the whites had a decidedly blue cast to them compared to the same movie streamed on my iPhone which appears to correctly display a truer white. Thanx in advance for your replies.