As long as you don't have white shoes and accessories it will be fine. Find a green scarf or wrap or jacket to wear with it for photos so that you are clearly dressed in green and a green hat or fascinator.
It's great to see M&S returning to classy clothing at affordable prices after all the sea of garish, luminous, embroidered, flounced and sequin-covered tat it's been touting for the last 15 years.