Since MIUI 12, MIUI enables a system flag to forcibly "convert" light app resources and assets to darker colors. This causes graphical issue in several apps, which is why this is just a developer option in AOSP.
Unfortunately, it seems Xiaomi don't care about third-party apps, other than the ones they've whitelisted to disable by default inside MIUI's code.
Despite the setting being modifiable with an ADB command, MIUI resets the setting on boot - hence the need for this Xposed module.
This module stops MIUI forcing nonsupporting third-party apps to display darker colors.
For MIUI 12 and Android 10 only.
Take a look at the source code if you want to know what MIUI code's hooked to achieve this - It's fully documented.
As this was a fairly simple mod, I've chosen Java over Kotlin for reduced app sizes and performance overhead.
Enjoy!