My phone says version 12.4 with no available updates and when connecting to iTunes it says the same thing. It says next next update on 1/16/2020
iPhone 6 Plus, iOS 12
The iPhone 6 is not compatible with iOS 13. iOS 12.4.4 is the highest possible.
The iPhone 6 is not compatible with iOS 13. iOS 12.4.4 is the highest possible.
That feature requires iOS 10..13 that your iPhone 6 can't install.
Is too old this is the reason
Your phone is up to date. The iPhone 6 cannot be updated beyond iOS12.4.4. You need at least a 6S to get iOS13.
IPhone 6 plus is listed on the website as one of the phones eligible for the dark screen. I can make my screen dark but the bubbles are orange instead of blue and the other apps are colored
It's not, sorry. The Dark Mode is a feature of iOS 13 and iOS 13 requires atleast the 6s or 6s Plus (looks similar to a 6 or 6 Plus) or the SE.
See following support articles:
Dark Mode (What's new in iOS 13) https://support.apple.com/guide/iphone/whats-new-in-ios-13-iphfed2c4091/ios
iOS 13 and iPadOS are compatible with these devices https://support.apple.com/en-us/HT210327
The exact reason is that your iPhone 6 Plus doesn't have enough RAM to support iOS 13. Your phone is too old, and you need a newer iPhone generation to get iOS 13.
Why can't I update my iPhone 6 Plus to13.3?
