I'm having the same issue with the 'Adjust Appearance' option. For the majority of my notes, it works fine, but for those where I set a black background, the color resets every time I restart the application! Other colors work fine, but black... no luck! Well, I've still done some investigating! If you choose the predefined black color (basic, web), it doesn't work. But if you set the color in custom with 0 0 1 (or more), it works, the color persists upon restart. If you enter RGB as 000, black disappears....
I'm having the same issue with the 'Adjust Appearance' option. For the majority of my notes, it works fine, but for those where I set a black background, the color resets every time I restart the application! Other colors work fine, but black... no luck! Well, I've still done some investigating! If you choose the predefined black color (basic, web), it doesn't work. But if you set the color in custom with 0 0 1 (or more), it works, the color persists upon restart. If you enter RGB as 000, black disappears....