1996 – For the first time in major league history, the regular season opens in March with the Seattle Mariners beating the Chicago White Sox in 12 innings, 3 – 2, at the Kingdome. Five Mariners pitchers strike out 21 batters, with Randy Johnson collecting 14 Sox in seven innings. The American League unveils its new colorful red polo shirts for the umpires, part of the “What a Game” campaign to lure fans back to the parks. The last sartorial change was in the 1970s when AL umps wore red blazers for several years. National League umpires will stick with traditional blue.

On March 31, 1996 — 1996 – For the first time in major league history, the regular season opens in March with the Seattle Mariners beating the Chicago White Sox in 12 innings, 3 – 2, at the Kingdome. Five Mariners pitchers strike out 21 batters, with Randy Johnson collecting 14 Sox in seven innings. The American League unveils its new colorful red polo shirts for the umpires, part of the “What a Game” campaign to lure fans back to the parks. The last sartorial change was in the 1970s when AL umps wore red blazers for several years. National League umpires will stick with traditional blue.

Sources –
Baseball Reference March 31
SABR Games Project
National Pastime March 31
Retro Sheet
Replay The Game