Tomorrow's celebration comes days before the postal voting referendum, which will run from Thursday to June 5.
Prosper Northland spokesman Barry Trass told the Northern Advocate last week the parade the trust had organised was only loosely linked to the Hundertwasser building proposal.
Mr Trass said the trust was not solely concerned with the Hundertwasser plan and the idea behind the parade was to highlight Whangarei's colour and character.
"We just wanted to have a parade that celebrated living here and gave people a chance to express that," he said.
Mr Trass said Prosper Northland was not involved with another pro-Hundertwasser group, called YES!
A YES! press release being circulated by email and on Facebook calls for Whangarei to be transformed into a "city of colour in the last week of lead-up to a binding public referendum".
The press release, from the loose group of volunteers who support the Hundertwasser project, refers readers to the YES! website it manages.
In reply to queries from the Advocate, a representative of the group confirmed that YES! is entirely different from Prosper Northland Trust and there are no people from that trust involved.