While baseball is not a contact sport, both teams having the same colors can become confusing. I was the plate ump in a lota' something to nothing game :
SCENE: Lead team had bases loaded with one out, both teams wore the same shade of blue, player was coaching first.
ACT I Grounder to SS , fires to 1st to get batter-runner, runners move up.
ACT II Grounder to 2nd baseman, he steps on bag, base ump calls out, fielders leave.
ACT III As 3rd base coach (their head coach) ran by me , he said : "I don't think we had any runner at 1st, but that's OK I want to get home,too".
ACT IV Shortly there after game ended; I informed the base ump that he had probably called the 1st base coach out on a 'force play' at 2nd.
ACT V He responded : "I was surprised that he wasn't running
".