Change default "Dark mode" background color

How-to
1

Description

Hi there, I am trying to change the dark mode background. I can create different themes, but I want to change the default bg for dark mode.

What MCU/Processor/Board and compiler are you using?

Custom board with STM32F769 and CubeIDE (Eclipse)

What LVGL version are you using?

Version 8.1+ (Latest master)

What do you want to achieve?

I want to set the background color of the theme, more spesifically for dark mode. If possible, changing the default for the non-dark mode will also be nice.

What have you tried so far?

I tried registering a new theme, and changing the style of the screen. The screen bg seems to change, but the background of the widgets I create still take the BG color from the default dark mode color.
Can I change the background of the widgets for dark mode within the theme?
I was hoping not to individually change styles for everything.

Code to reproduce

	lv_theme_t * MyTheme = lv_theme_default_init(MyLCDDisplay, lv_palette_main(LV_PALETTE_BLUE_GREY), lv_palette_main(LV_PALETTE_ORANGE), true, LV_FONT_MONTSERRAT_28);
	lv_disp_set_theme(MyLCDDisplay, MyTheme);
	lv_obj_set_style_bg_color(lv_scr_act(), lv_palette_main(LV_PALETTE_BLUE_GREY), 0);