Answer:
He wore his black suit, another color of shirt (not purple) and shoes
Explanation:
Holmes owns two suits: one black and one tweed.
Whenever he wears his tweed suit and a purple shirt, he chooses not to wear a tie and whenever he wears sandals, he always wears a purple shirt.
So, if he wore a bow tie yesterday, it means he wore his black suit, another color of shirt (not purple) and shoes because the shirt color is not purple