UI Widget rendering significantly darker (4.10.4)

I have an UI Widget that basically shows me a few variables. The player does not interact with it, but just reads out values from it based on some (nice) animations. The thing is that it appears very dark and at some point some elements of it did look correct. Because I had parts of it show up correctly at some point, I don’t think it has to do with lights. I also changed the color of one of the elements to white, so even if it were a gamma issue, I don’t think it would look this wrong. I suspect that the widget is in a mode that sets it to “inactive” and it appears darker because of that.
I have set it to Volatile (for animated components), “is Enabled” off and collision off, because the player is not supposed to interact with it. Does anybody have an idea of what I could do to show up with the colors that I picked in the Designer view of the widget? - The widget is also supposed to be of an “unlit” material type.

So it seems that the layers have to be set to “Is Enabled”. Which is strange, because the tooltip says that the tickbox is about whether the object can be modified by the user. So I guess there is some kind of bug going on.