Hello @OrlyN ,
Unfortunately, dark mode is something done by the email client / app itself, so we have no control over how it will automatically force a campaign's colors to be different. The only way to potentially get around this is to use as neutral of colors (black, gray, white) as possible while building your email. Otherwise, the apps are generally not sophisticated enough yet to recognize they might be changing text colors, etc. to be hard to see against certain background colors you've selected.