Certain elements have the same colour with the background, causing problems in some programs.

[MikeWalrus]

These are really nice themes and are very easy to build!
However, I notice that some buttons don't show up even if they should be "highlighted".
For example, in Xournal++, it's impossible to tell the difference between selected buttons and other buttons, giving me a hard time deciding which colour or tool I am using.
These are two screenshots of Xournal++'s toolbar.
With the palenight theme:

And the adwaita(dark) theme:

[jaxwilko]

Hi @MikeWalrus, what version of Gnome/GTK are you using? :)

[MikeWalrus]

Should have mentioned the version. :)
It's GTK 3.24.33.