Discourse app icon changed

I use an app version of Zynthian Discourse. About a week ago the icon changed. It used to be black but is now white and difficult to see. What changed and why? This is on an Android phone.

I didn"t change anything. My android shows the black icon as ever.

Screenshot_20220122-022500_Google

This mine.

I installed fresh on a new phone and still see the white.

Could it be that the default dark/light mode may have been flipped in a recent Android update?