Describe the bug
Some Programs make use of single-colored jump list icons, whose color gets automatically adjusted to which one is needed. Let's look at MS Teams, for example. When you search for it in the Win10 start menu, which has a white background, the icons are displayed as black:

And when displayed on a dark background, e. g. when on the taskbar jump list, they are white:

Open Shell, on the other hand, always displays them as white, which makes them look invisible on white backgrounds. Here, on this slightly blue-tinted background, you can just barely make them out:

Possible solution
I don't know how Windows accomplishes it. But if Open Shell wants to implement this behavior accordingly, I think by default it should look at the contrast between the white icon and the background it is displayed on and, if too low, render it in black. However, it should be overridable in skins.