Laumatia said that while he had not lost any direct family from the outbreak he had spoken to others who had.
"This epidemic has taken a dreadful toll on Samoa, particularly on the country's children. I want to help ensure they get the help and support they need.
"This is a way to raise money to achieve that, and wearing a brightly-coloured shirt will also be a visible demonstration to the people back home that we're thinking of them in their hour of need."
'Alofa Atu Day for Samoa' means love to you and Laumatia said it was about sending as much love back to Samoa and the people affected as possible.
He is urging other businesses to join in as well.
"Our message is if you can join in that would be really awesome. We haven't seen a tragedy like this in Samoa before."
Laumatia said the hardest thing for him was that it was a situation that could have been prevented.
Measles has killed 72 people in Samoa since October, in a deadly catastrophe that has highlighted the country's low vaccination rates - just 16 per cent had both doses of the measles vaccine last year - and the influence of a growing anti-vaccination movement there.
"Any business big or small able to contribute and send some love would be appreciated."
Other banks, including ANZ, ASB, BNZ, Heartland Bank, Kiwibank, MUFG, Rabobank, SBS, The Cooperative and TSB have also pledged their support and will be running fundraising activities.