What color for groomsmen

My theme is juniper ( dark green ) with sunflowers ( so yellow )

My bridesmaids are in the dark green with sunflower bouquets

And the men will have a sunflower pinned on them

What color would go well with the green?

None of them men are wearing jackets.

We are doing suspenders and long sleeve shirts

What color would go well with this?

I didn’t want to settle for black.

Btw it’s a fall wedding! ☺️☺️

I felt as if the sunflowers will pop against such a. Dark green.

And we have lots of ivy, and greenery at the wedding.