A navy suit with brown shoes connects jacket, visible waistcoat and trousers into a larger dark area. A pale shirt and dark tie divide the middle, with a narrow pale chest accent as well. The complete view makes the relationship between trouser end and shoes especially useful while one hand stays in a pocket. It offers a colour relationship rather than a personal measurement for your hem.
Try a similar dark arrangement with existing brown shoes first. Compare a darker pair afterwards if you want that option. Keep shirt and trousers unchanged so the lower difference stays clear. For an actual wedding, place confirmed host expectations beside this own preference. Brown is neither prescribed by the photograph nor automatically excluded by the dark outfit. You can assess both through the complete combination.
Walk, turn and sit in the actual trousers. Check the hem after standing with your hands free. Add what you will carry in pockets before assessing the whole contour. If you expect to remove the jacket, inspect the waistcoat separately with the same pieces. The full view then becomes an understandable trial of your own outfit.