By looking at the St. Paul's Cathedral concept art piece that I did, I have used it as a reference for making this screenshot design. I didn't spend quite as long on it as I did with it originally, but I think it still looks like the same setting. With regards to the actual UI, I tried to make it look quite unique through the boxes in which the weapons/ammo count, level and health bar are, and by having the map as a compass in the top left. I think in this instance they have some issues standing out from the background.
As you can see from the two images below, I draw the background and UI separately, as I thought it would make it easier when adding colour, which I believe it did. However, it is probably due to this as to why the UI has issues standing out.