Dark themes are not working

Hello! I am trying to figure out themes in iced. The problem is every dark theme have solid black background. Text and button colors are changing according to theme. Light themes are looking ok. Example of GruvboxDark theme:
image

My example app code:

use iced::{widget::text, Element, Sandbox, Settings, Theme};

#[derive(Debug, Clone)]
enum Message {
}
#[derive(Default)]
struct MyApp {
}

impl Sandbox for MyApp {
    type Message = Message;

    fn new() -> Self {
        MyApp::default()
    }

    fn title(&self) -> String {
        String::from("MyApp")
    }

    fn update(&mut self, _message: Message) {
    }

    fn view(&self) -> Element<Self::Message> {
        text("My App").into()
    }

    fn theme(&self) -> iced::Theme {
        Theme::TokyoNightLight
    }
}

pub fn main() -> iced::Result {
    MyApp::run(Settings::default())
}

I tried 0.12.1 and 0.13.1 iced versions with the same result.

Is you issue that every theme has the same background or that it just has a solid background?

Every dark theme has the same background (solid #000000 color)

You can create your own custom theme with whatever colours you like with the Custom(Arc) theme and you can take one of the existing Palettes and tweak the background color.