I have them, but in relevant colours, white on front, yellow on back, still metal plates, with the german style lettering. With the D in the left hand side. I haven't had a problem with them and i live in surrey where every copper is out to get you.
As long as they are the right type then you shouldn't have the hassel, and if you do get caught and have the means to change them back to your old english plates there is not a lot of point worrying.