Canadians are joining an online campaign to demand that Kraft ditch the food colour from its trademark boxed cheesy noodle product. But so far, the company behind Kraft Dinner says it has no plans for change.

The campaign began earlier this month when two food bloggers from North Carolina, Vani Hari of Foodbabe.com and Lisa Leake of 100daysofrealfood.com, started a petition on Change.org. They wrote that they believe Kraft Dinner would be a healthier, more natural product without the artificial food dyes that give it its characteristic orange colour.

The women think it’s odd that Kraft Mac & Cheese – as Kraft Dinner is called in the U.S. – contains artificial food dyes such as Yellow 5 and Yellow 6, while the same product sold in the U.K. and Europe contains natural colouring.

The women say they conducted a taste test comparing the Kraft Mac & Cheese sold in Britain and the product sold in the U.S. They conclude that the products taste and look almost identical.

“Kraft reformulated their product for the U.K., but not for their fellow American citizens. It’s time we demand the same here in the U.S.!” the women wrote.

“Our kids deserve the same safer version that our friends get overseas!”

The bloggers say food dyes are derived from petroleum and that studies have linked them to an increase in hyperactivity in children, poor brain development and long-term health problems such as asthma, skin rashes, and migraines.

Their petition demands that Kraft switch to natural colouring. And so far, close to 275,000 people have signed on, including nearly 25,000 Canadians.

In its products sold in the U.K. and Europe, Kraft does use natural colouring agents, such as paprika and turmeric. But the company says it’s confident the dyes used in Canada and the U.S. are safe.

“We carefully follow the laws and regulations in the countries where our products are sold. So in the U.S., we only use colors that are approved and deemed safe for food use by the Food and Drug Administration,” Kraft said in early March in a written response to the petition.

The women say that in Europe, foods with dyes require warning labels stating the colourings “may have an adverse effect on activity and attention in children.””

In Canada, food colouring agents need to be specifically listed on the label to inform those with high sensitivity to food colours.

Kraft posted a letter on its website saying it offers 14 other versions of Kraft Mac& Cheese that contain natural or no food colour, including Mac & Cheese Organic White Cheddar. And it says that its consumers don’t want them to make changes that would affect the taste they expect.

The women said on their blog earlier this week that they can no longer get the company to respond to their requests for a meeting to discuss changes. But they are are vowing not to give up.

“Their lack of response is not going to stop us from trying to get them to take the lead on this small – yet significant and positive – change for our food industry,” they write.