AMOLED and UIs with dark modes have skyrocketed in popularity in the smartphone market over the years, mainly based on the idea that both are easier on battery life, particularly when combined. A new study published by Purdue University engineers question this rationale, albeit under certain conditions only.
https://www.notebookcheck.net/New-research-challenges-the-theory-that-dark-mode-on-OLED-saves-battery-on-a-smartphone.553003.0.html