Note that he is wearing a velvet DJ with his black pants. (Obviously, I hope, you can't wear a velvet DJ with velvet pants.) This is semi-correct except that velvet DJs are only supposed to be worn at private gatherings among friends. Mr. Plummer is, no doubt, extremely popular. But the Oscars still don't qualify.
There are three ways it is more-or-less acceptable to wear a DJ with non-matching pants: When you are wearing a white DJ, When you are wearing a velvet DJ and when you are wearing a Black Watch DJ. Otherwise, not.
So no, you can't wear a midnight blue DJ and black pants, it will look ridiculous. Trust me on this. You should also know that midnight blue, shawl lapel tuxedos are pretty rare so you are going to have a very hard time finding one OTR.
Herein follows the obligatory recommendation of http://www.blacktieguide.com