[smoldesu]

(Warning: I am not a display technology expert)

I'm guessing it's a combination of yes and no. OLED screens save power on black colors because it can completely shut off the pixels responsible for illuminating that portion of the screen. If you have a slightly brighter color than pure black, the diode will turn on but not at full-brightness.

Technically speaking, you probably stand to save the most power on a purely black background. You're still saving power on other dark colors, but it's probably more noticeable with pure black.

[9wzYQbTYsAIc]

I found the following research paper that does seem to support your educated guess:

Energy Aware Color Sets

https://eprints.cs.univie.ac.at/4187/1/eg09_color.pdf

[fortnum]

Could you point me in the right direction please? It does talk about OLED, but I couldn't find where it specifically referred to the question here.

[9wzYQbTYsAIc]

My pleasure, hopefully this answers your questions, but if not, I’ll check back to see if you ask a follow up question.

From the “Applications and Results” section towards the end of the paper:

“Figure 9 documents the energy consumption of the three images of Figure 8. Energy consumption is measured according to our energy model from Equation 1, using various grid sizes. The most prominent observation is the substantial energy savings achieved by colors chosen according to our continuous optimization approach. Across the different grid resolutions, we save on average 41 percentage of energy compared to using ColorBrewer colors.”

[fortnum]

Thank you very much

[gloryjulio]

The problem is that I find it really hard to read. The contrast is too large for the eyes. Some background color and lighting makes reading more comfortable. Perfect black is good for video though

[nivertech]

I'm reading this on an X1 Carbon with the OLED screen. The pure black is sometimes unsetting. Sometimes I'm adding brightness but the black stays black, on the IPS screen the black would've become gray which gives you visual feedback, but on OLED there is no such feedback and you think it doesn't work.

I switched everything to the dark mode, not because I like it, or want to save the battery, but because I afraid that the pixels will burn out.

When the laptop is booting it uses the full brightness, also some bootable Linux distros use the full brightness, as they lacking OLED-aware display drivers.

I also enabled auto hide for Ubuntu 22.04's taskbar, not sure for to do it for the topbar.

I use a very low brightness levels ~ 15%, otherwise the colors are too vivid for my taste.

I think dark mode on OLED somewhat saves the batery, but I'm not sure how much. I didn't measured it.

[fortnum]

Thanks, that's exactly what I am wondering

Is #010101 effectively #FFFFFF or does it actually use less energy the darker it is? With LCDs we know it is the former, but what about OLED displays?

[danudey]

The brighter the pixels are, the more power they are using. A pixel uses 0 power at 0 brightness, and it goes up from there.

[fortnum]

Well, with LCD it does not matter. It always uses the same power. Hence the question.

So you are confirming that the statement is actually wrong. The darker a pixel on OLED, the less power it uses. Right?

[smoldesu]

I'm not sure. Considering what I know about OLED, I'd assume that #010101 consumes considerably more energy than #000000 since it needs to emit light for that individual diode. The energy efficiency from there will mostly depend on the brightness/size of the display.

[fortnum]

But does it use less power than #FFFFFF?

[smoldesu]

Yes, but it's efficiency scales with the overall brightness of the display. True OLED black will always consume the same amount of power, regardless of brightness.

[skavi]

The active matrix still has to be powered up with 100% black content.