Hello @DougA172 ,   Please keep our Community Guidelines in mind when posting to our public forum.   I'm not sure which legacy UI you'd be referring to, because even our 2nd Generation Editor that retired years ago was setup to change colors with email programs' dark modes - as is the expected function. There's been no "upgrade" or other change on our end that would be affecting how email programs treat dark mode, because it's still functioning the same in this current editor as it did with the long-dead 2nd gen.   Emails apps in particular function with the expectation of inverting colors to provide a darker background. It's part of the reason a lot of major companies and orgs default to the standard white backgrounds, black lettering, and blue links to ensure visibility in both light mode and dark mode's inversions. If an email app is still displaying an email with a white background and black lettering in dark mode, either it's glitching, the original email already had inverted coloration and is trying to override the email app's functions, or the entire email is just an image and thus can't be inverted.    If you're wanting the images you've included at the top and bottom of your email to blend more seamlessly between light and dark modes, I'd recommend using / creating a version with a transparent background.   You say that you had you iPhone on dark mode, but was your particular email app also set to default to dark mode? The reason I ask is that unless you set the app to adopt a phone's styles, it will usually just default to light mode. Is your issue occurring in other email apps you have access to?   If you need additional insight on how dark mode affects emails, see our support article on the topic, or you can check out your email apps' support articles on the topic, if available. ... View more