This market resolves as yes if anyone shares a link to an image generated by DALL-E 3 that is completely monochrome (e.g. completley black). Both ChatGPT and Bing image creator are fine, as long as it's DALL-E 3.

Good luck!

Edit (10/29): There were quesitons around whether all pixels needs to be the exact same RGB value. The answer is no, however - the image should still appear monochrome after auto-leveling it. You can use a free tool here: https://www.imgonline.com.ua/eng/auto-levels.php