Some of these flags have been around for several months now, but as Chrome Unboxed reports, Google has made significant strides to improve them in the past few weeks (as you can see in the below image). Eventually, web pages will be able to automatically change colors depending on the Chrome OS theme selected by the user.  If you have a Chromebook in the developer channel and want to check out dark mode yourself, you can do so by navigating to chrome://flags and searching for these flags: Force Dark Mode for Web Contents, Tab Outlines in Low Contrast Themes, Prominent Dark Mode Active Tab Titles, Security interstitials dark mode.  Dark mode for Chrome OS is still very much a work-in-progress, so don’t expect the best results off the bat. In fact, some users have reported that the “Force Dark Mode” flag was pulled because it broke other features.  Dark mode for Chrome is cross-platform, which means it will be available on Chrome OS, Mac, Windows, Linux and even Android (sorry, iPhone users). With its Chrome 73 update, Google brought its dark mode to macOS. Now, dark mode for Chrome will automatically activate whenever macOS’ native dark mode setting is enabled on your Mac computer. Dark Mode for Chrome is also available on Windows 10 (check out our guide on how to enable it) and is an experimental feature in Chrome for Android. 

Chrome Dark Mode: How to Get It and Other New Themes