Using #000 would save the maximum power for any device with an OLED panels (like my laptop and my smart phone). Given that the idea is to keep a device on and s

Using #000 would save the maximum power for any device with an OLED panels (like my laptop and my smart phone). Given that the idea is to keep a device on and some screens not being smart enough to understand this is an okay time to power down, #000 would be the only ethical color scheme to use. If you added a jitter to the placement of text over time, you could prevent possible burn in as well.