On a recent Saturday night at Citi Field, the Mets rolled out the red (and orange, yellow, green, blue and violet) carpet for the gay community. The Coca-Cola sign in the outfield was lit up in rainbow colors. The Kiss Cam was filled with same-sex couples smooching. The color guard carried a rainbow flag. And gay officers from the New York and Nassau County Police Departments were honored, as was a gay war veteran.

The Mets are hardly alone in offering such welcoming gestures. The N.B.A. had its own float, with Commissioner Adam Silver aboard, in the Pride March in Manhattan last month. That same day, the Cubs’ World Series trophy — draped in a rainbow flag — rode on a float in Chicago’s parade. And many sports teams, including a large majority in baseball, have hosted gay-themed events.

But one team that has not done so is the Yankees, even though their city helped give birth to the modern gay rights movement.

That most teams have chosen to stage a pride day or night at their ballparks is not surprising, because thematic promotions to draw fans have long been part of baseball’s culture.