Four years ago in Australia, red dominated the stands during the Test matches, prompting the Australian Rugby Union to hand out free yellow scarves to Wallabies fans.
Graham Henry coached the Lions that year and is well aware the lift it gave the players to see the stadiums bedecked in red.
He said Kiwis should not underestimate the part their efforts could play in helping New Zealand teams to victory.
"Fans can help the players on the field with their colourful presence and with the noise they make," he said.
"We must ensure we keep the home ground advantage. These factors can make a difference," he added.