Will B&W center match Paradigm Monitor 5

No, you can't match brands. I've sold extensively both the Paradigms and B&W's over the years, and know em all! You'll never build a believable sound stage across the front by mix/matching. You'd be better off with upgrading all to one brand, or even better, 3 identical speakers,if you don't like you're Paradigm center.
Good luck

I agree entirely with the above poster.

I personally use an old Kef Reference 80 Center speaker and Soliloquy 5.0s speakers for mains and Bose Model 100's for the rears and It sounds great. And, YES, I have owned Matrix HTM Center, Matrix 802S3 Mains, and B&W DM600i rears and maybe it sounded marginally better.

Don't be discouraged by popular audio opinions. Much that is out there will not only work but sound great!