Does This Combo Work?

Hi Apes, 

My girl is graduating soon from university and I've been invited to attend, I don't want to wear anything I wear to the bank because I don't want to mingle the work environment with the social one, but the dress code is relatively formal and so I thought I'd piece together something from what I don't normally wear.

Right now I'm thinking of wearing a dark grey double-breasted jacket (which I bought as a standalone piece) with some black chinos, a white shirt, an accented tie, a brown belt, and some brown shoes, maybe a black pocket square too. I don't own any black shoes anymore, does this matter? Should I just get some rather than brown?

Thoughts appreciated from the more stylishly literate amongst you all. Cheers.