We asked people what they thought of Anchor's limited edition black All Blacks' Rugby World Cup bottles. Did they think it was off-putting or a good boost for the national team?

Consumers are souring to the taste of Anchor's All Black Rugby World Cup promotional bottles of two-litre milk, Wellington dairy owners say.

Thakor Gopal, owner of Island Bay's Hy-Grade dairy said the marketing campaign was costing him sales, which he estimated had dipped about 20 per cent since the black bottles were launched earlier this month

Gopal said some of his customers were put off by the idea of milk in a black bottle.

MONIQUE FORD Dairy owner Thakor Gopal says Anchor's limited edition All Black promotional bottles are costing him sales.

"They say it should not be in a black bottle - lots of people are unhappy."

Black also camouflaged the bottles, meaning customers could not see the product, Gopal said.

Dinesh Patel, owner of Newtown's Jimmy's Fruit Mart reported a similar sales slump and said some customers thought the milk itself was also black.

"They think it's black milk inside, people don't want this packaging," Patel said.

But the big supermarket chains were not reporting any sales slumps, or spikes.

Foodstuffs corporate public relations director Antoinette Laird said it was business as usual at its New World and Pak 'n Save chains.

Laird said the company had received no negative customer feedback on the black bottles.

A Countdown spokeswoman said there had not been "too much of a difference to sales".

"Our customers are used to buying their milk in transparent or white milk bottles, so the black bottle is new. However, a large number of our customers are All Blacks fans and are enjoying this limited edition bottle," she said.

Opinion was split on Twitter with many getting behind the drive to support the All Blacks and others feeling squeamish about the black packaging - and the excess of nationalistic sporting pride.

In a statement Fonterra brands marketing director Clare Morgan said the dairy giant was "thrilled" with Anchor's sales.

"What's even better is the number of people talking about the Anchor black bottle and sending in selfies with bottle. It's early days but we're hoping more and more Kiwis will want to pour some national pride on their breakfast cereal, or into a glass as they watch the All Blacks take on the world."

Associate psychology professor Marc Wilson said black packaging made the product stand out.

Black had a particular cultural association for New Zealanders, Wilson said.

The colour was linked to sophistication and upmarket spending, but this positive association depended on the product and Wilson was not sure milk and black gelled or jarred with consumers.

"We use colour cues as markers for hygiene. Would you eat a fluorescent pink banana? Maybe, but probably not if you had a natural coloured alternative."

Colour-related reactions to foodstuffs were ingrained in our evolutionary DNA.

"While black can signal sophistication, I'm not sure that's an attribute commonly considered when purchasing a brand of milk.

"Just as black can signal sophistication, white is typically associated with purity. On the one hand there's research that I would argue says the All Blacks get a psychological advantage from their black gear, but I think the connotation is lost on a milk product. In fact, there is the risk that it is counterproductive because the traditional advertising colour of milk is associated with purity," Wilson said.

Australian neurobranding specialist Peter Seidl said regardless of people's visceral reaction to milk in a black bottle Fonterra had succeeded with the campaign as they had got consumers talking about what was essentially a "boring product."

In any other country the novelty of a black milk bottle would fade fast but because the All Blacks were seen as "a national treasure" the branding could stick if Fonterra could bring real meaning to the campaign, Seidl said.

DOES IT MATTER IF IT'S BLACK OR WHITE? WHAT YOU SAID

"It doesn't make me want to drink it, it kind of puts me off."

"I like it, I like black."

"It's a pretty good way of supporting the All Blacks."

"I think it's unnecessary and silly."

"It's a good idea and a great promotion but the blackness is a bit off-putting."

"I don't like the black bottles in my white fridge."

"It's a bit different, you certainly notice it in the supermarket."