Save icon with themes (background/foreground color for standard, dark mode, OLED, etc). And save as PNG

[ensimo]

Kind of issue

• Feature
• Bug
• Design
• Other, namely:

Description

It would be very useful to have, in the site toolbar, the possibility of applying a theme to the icons before downloading.
Currently when I download an icon, for example WhatsApp, it has a white background and a black image. I would really like to be able to choose a theme, perhaps 'dark' or 'OLED' where customize preset of background and foreground color.
Please, also consider the possibility of saving the files in PNG format

I'm using your icons on macOS, when I save link in Safari 'Save on Dock' i can customize icon, default icon is favicon white mode.