Which color space the IOS devices is used?

When I use the MAC Digital Color Meter to detect the RGB color of the screen, the RGB values can be shown in sRGB, Adobe RGB, original RGBs spaces, etc. And they are slightly different.

I want to use these values in the iOS Xcode platform, and use UIColor class to represent them, which color space should I choose in the Digital Color Meter?

Thanks.

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