DH has a similar version of this linen jacket to wear to a wedding. It is greenish linen with a vague blue and red check. He is wearing a white shirt underneath it and it is a casual wedding but I am thinking he probably needs a tie.
www.austinreed.co.uk/fcp/product/austinreed/All-Jackets--%3E/Green/Blue-Overcheck-Jacket/11974