[marcusjt]

Yes but whether dark is more efficient or not depends on screen technology, plus there's battery level, viewing conditions and user preferences to factor in, so ultimately it's up to the phone OS / supporting software to make smart decisions about what's the right theme to show at any given moment.

[soulofmischief]

That seems a bit orthogonal to my statement.

Regardless of specific hardware implementations, it can be agreed upon that patterns which can cause some non-negligible amount devices to be less energy efficient are anti-patterns.