Youth leader Hope Sexton, 18, said the murals were the group's "first big community project".
"It's really exciting for us to start something as a team and finish it. Hopefully, this isn't the last you'll see of us."
In her speech at the unveiling, Miss Sexton said the young people were initially unsure of their artistic abilities.
"They kept saying, 'I can't draw', 'or I'm not good at art.' But, once they got going, they proved themselves wrong. Realising what they were capable of was an amazing experience for them."
The youngsters chose to make the words "Mana" and "Respect" the main focus of the murals, and added some "inspirational phrases" such as "Kia Kaha", "Make Good Choices" and "Be The Change".
"At first, they said they couldn't think what they wanted - but they got inspired," Miss Sexton said.
"They were the ones who chose those words, not the adults."
South Wairarapa Mayor Adrienne Staples, Featherston Community Board chairwoman Lee Carter and Alternative Education teacher Paul Adamson also gave speeches.
Mrs Staples mentioned a quote she had heard from a young person at a conference: "All humans are the same because they've got a brain, but different because they've got a mind. Your minds created this wonderful piece of art - you should be proud of yourselves."
Miss Sexton, who was a youth representative of the council's graffiti working party, said the youth group was formed to help combat youth crime, such as tagging.
She said rates of tagging in the community had "come down drastically" in the seven months since the group started.
"Things like this are cool, as young people can see graffiti can be an art form, rather than vandalism."
The youth group has also painted a mural at the Featherston swimming pool. This week they host a skincare workshop and skateboarding demonstration for National Youth Week.