Can we make a computer screen light in color when turned off?

There's one problem and that's how our eyes work. They need photons to enter them to be able to see. The photons are being "reemitted" by the body we look at. The body absorbs the light shining on it and just reemitting the photons that aren't absorbed by the body's surface. So, actually, what we perceive as color are photons that haven't been absorbed by the body.

Black screen means it absorbs everything. Because it's a translucent body consisting of a few layers, the light simply gets trapped within the layers and is not reemitted into our eyes. We perceive that as black.

If you want to make it whatever color, you need a not translucent screen, so the photons are partly absorbed and partly reemitted. Then we have some photons in our eyes and sensations that can be interpreted by our brain as information/color/whatever.

The screens of e-ink utilize that. But they're slow.

So to answer your question, no it's not possible to make ordinary screens to have a color, except there's a solid body in front of the layers to absorb and reemitt the photons.

To build a screen like that, one would need a backlight. No matter where it comes from. Or, inverted LCD on a white plane that alters the refraction when there's a current flowing. That would consume more energy because all the pixels need to be constantly powered (and after powering off, they would automatically alter their refraction..)

So, no..

What about constantly low powered screens like Samsung's the frame?

If you just want a different aesthetic when your system is powered down, you don't need to change the screen itself - just drape a piece of cloth over it.

Your typical e-ink screen will be white when turned off. I think transflective LCDs too, or alternative display techs like https://daylightcomputer.com/

You can get monitors using those technologies if you don't want it to be black when off.

I mean, the absence of light is darkness, and light requires energy. That's why screens are black when they're off -- there's no energy source. The alternative would be constant energy drain for no reason, or something like e-ink (but that's expensive and afaik incapable of producing color).

With the right set of engineering requirements, yes. But typical engineering requirements preclude it because typically opposed features are more important for a display.

And for some use cases, placing a sheet of white paper over the display might be good enough. Good luck.