He said finding out exactly where they were - among about 132,000 signs spread around the Super City - would cost money which would be better spent on other activities.
They would not be replaced, at a cost of about $180 each, unless there was a demand from local communities.
The spokesman said that until Auckland Transport decided mid-next year whether to adopt green or blue as its standard throughout the region, its policy would be to replace like colour with like when signs were damaged or worn.
"It is unfortunate that some green signs have gone up, and these signs will be replaced only if there is a demand from the local community for this to happen," he said.
Neither did Auckland Transport intend consulting the public over a preferred colour.
That is despite a call last week from Orakei Local Board leaders, whose territory includes the Glendowie intersection, for them to be consulted.
Auckland Transport says about 63 per cent of the Super City's streets signs are already green, which was the official colour of the former Waitakere City, North Shore City, Manukau City and Rodney District.
Blue was the colour of signs in the former Auckland City, and the Papakura and Franklin districts.
Once Auckland Transport decides which colour to adopt, it expects to take several years to switch over in the course of normal maintenance, as replacing 132,000 signs would cost more than $23 million.
The Herald yesterday found two green signs pointing to streets off Shelly Beach Rd in Herne Bay, and one on Pompallier Tce in Ponsonby, next to a blue sign pointing to John St.
At the Glendowie intersection, which has two green signs and an old blue one sharing the same pole, blue is likely to be back by the weekend.
