Hello. In the options there is a setting to change the opacity of the dialogue background, and also change the texture to the default Ren'py one. This is under the "General" tab in the options.Thanks!
I'm sorry bt there's nothing like that. Is it only for pc version???...... Bt I'm actually an android player.
Seems there was a bug with mobile! I've fixed it and It'll come with the next release :)