I've used clear and smoked corners on my bimmers. After using the clear I think the smoked would be better to make it different and matches the euro depo lights (black) better. Currently using the clear for the winter time.
I like the euro red clear tail light from BMW. It's a little expensive but well worth it to make the ti updated and european.
Now for the side marker. I would also suggest the smoked ones to match the front corners. It would look nice on a silver 318ti.