Nationality flags colors change in dark mode.

I have wordpress elementor pro website with polylangs plugin https://villasaimaansini.fi.

If visitor uses dark mode, the flags in the header turn dark automaticly. I don't want that to happen. I haven't created any separate dark mode for this website.

How to make those flags be their original color also on dark mode?

https://preview.redd.it/kria90svkrod1.png?width=1920&format=png&auto=webp&s=e502d1dd2c492c56b26b42ffdea6e6d4b556b4c0

https://preview.redd.it/8ebfpk4xkrod1.png?width=1920&format=png&auto=webp&s=93e007ee6e84b4524d1f33e0c4f431ff76cafe05