I noticed a strange thing with UMG combo boxes: The color used for selected item in the list is taken from the UE4 Editor preferences → Appearance settings. I noticed that because this color was always orange in my UMG combo boxes, and I found no way to change it. As it turned out, this color can only be changed via the Editor prefrences… WTF?!
So, what is the intended way to set this color for production? This surely must be a bug! For a shipped game, there are no Editor preferences at all, right?
Hey Epic, any feedback on this?
After doing a bit of digging I was able to find that this is a known issue (UE-20556) and that it has been reported to the developers for further consideration. However, I will be sure to bump up the community interest for this issue. I do not have a workaround for this issue at this moment. I have provided a link below to the original issue. Please feel free to visit the linked thread for future updates. Thank you for your time and information.
Link: SComboBox doesn't have full skinning controls - UI - Epic Developer Community Forums
Make it a great day