A blue suit with brown shoes creates a definite colour change at the lower finish in this photograph. The person is seated, wearing a waistcoat, pale shirt and darker bow tie. A dark sock area remains visible between trouser finish and shoe. The pale bench adds another frame around the figure. For the colour comparison, the blue main area and brown shoes matter most, rather than reproducing the complete occasion outfit.
Put an actual brown shoe pair beside your own blue trousers. Wear both and check the transition standing and seated. A raised leg shows a different area from a straight stance. Decide which sock should fill the space and how clearly it may differ from trousers or shoes. Sock colour and height belong in the same specific trial.
Compare a darker shoe afterwards if you own one. You can then see whether you prefer stronger colour separation or a quieter continuation. Bow tie, pocket square and lapel detail are secondary to that comparison initially. Select them later according to the actual requirements of your event.