The recent Android update also support dark mode in the setting, and any phone that have the latest Android OS, if the broswer on the phone support night mode, this type of effect will occur.
I checked the privacy browsers:
- Duckduckgo
- Firefox
- Firefox focus
I have tried these broswers which are the recommended privacy broswers, but not supporting such night mode that will darken the sites the broswers are accessing. I know UC browser is not a privacy broswer, it is only used for downloads, but what about VIA, is it a privacy broswer?
About the dark mode, I am surprised by your words, it seems that you have experience with the application, thank you for mentioning this. BTW, not all phones can be upgraded. Mobile systems are not like computer systems. Unfortunately, the company providing the phone needs to do an update that is completely identical to the device, until now, not all devices receives updates.
About the Privacy, VIA uses Android System Web View (com.google.android.webview) which is built-in app. It's upgradeable on Andorid 5.0+ (lolipop). Android system web view for android <7 is a chrome external competent. For nought+, the app directly is using the google chrome in form of Android system web view, so Privacy is same as chrome now. Chrome isn't safe for OLD android versions, because OLD android systems aren't safe at all. So using any apps on them may be risky.