Many generations ago, there was a Tohuka named Tumaro who was gathering and preparing an Taua to build the Pa Matakiawhia near Nelson. On the eve of their departure Tumaro spoke to his Iwi and said a Karakia. He left his wife Rakaitekura behind for her safe protection.
Tumaro was away for a long time.
When he finally arrived back from his tribal quest he found his wife to be pregnant and he suspected her of adultery. When the confinement came on, the child was a long time in being born. Finally Tumaro began to Whakapae, that is, to name men he suspected of adultery with his wife. When he called out the name Te Aohikuraki, the child, a boy, was born.
Tumaro was deeply hurt and, saddened by Rakaitekura's unfaithfulness, he took her to the river and told her to wash and to prepare her Koukou. Rakaitekura did as she had been told. Rakaitekura came from a very high born line and carried the title Arikinui or Puhi. She was very beautiful with long flowing red hair. While she was bathing herself, Tumaro performed the Karakia to make her Noa.
During this Karakia a reddish colour started to appear in the river, flowing from her long red hair. Tumaro's Karakia had much Mana, Ihi and Kaha combining with his Wairua to change her to Noa. All of Rakaitekura's Mauri was flowing down the river into the Raukawa sea. Tumaro then returned his wife and her Tama to Te Aohikuraki and said: "Rakaitekura is now Noa like our Iwi but, your Tama is like you and me, a Arikinui. I have named him Te Hikutawatawa and one day he will lead his Iwi to new lands." So Tumaro departed with his Iwi back to Matakiawhia, leaving behind Rakaitekura with Te Aohikuraki and their new born son, Te Hikutawatawa.
From that day onwards, the river where Rakaitekura washed her long flowing red hair was named Koukourarata, and this red colour that flowed into the river formed Maukoroa.
This is the Kai Tahuiri tradition of how red paint was born.