system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does power saving use grayscale?

Companies such as Samsung use grayscale but doesn't that use more power than RGB? I thought so as gray is made up of all three elements but blue is just using the blue led? Why is this?
gpt
LCD screens have white backlights that are filtered through basically tiny colored foils.

If you want red. You shut the blue and the green subpixels.

And since the whole light comes from the backlighting, you basically shut out 2/3 of the generated light.

With greyscale, all subpixels are „opened“ equally and you get the most of the backlight, alowing to dim it and save power.