Kraft Foods Group is to remove two artificial dyes from three varieties of its Mac and Cheese character-shaped products in the US and Canada.

A spokesperson for the US food giant told just-food today (4 November) it has revamped its Shapes line for 2014, including using colours derived from spices, ie paprika, annatto and turmeric.

They will also have six additional grams of whole grains and be lower in sodium and saturated fat. The improved line will be available from January.

"Parents have told us that they would like fun Mac & Cheese varieties with the same great taste but with improved nutrition," the spokesperson said. "For many years, Kraft has been reformulating hundreds of products to deliver better nutrition. These Shapes products are our latest innovation and provide additional choices for Mac & Cheese fans of all ages."

Kraft had previously used Yellow 5 and Yellow 6 in three of its kid-friendly varieties of macaroni and cheese. However, a campaign launched by two North Carolina bloggers, Lisa Leake and Vani Hari, called for the removal of the artificial dyes. The pair opened an online petition, which has been circulating since March.

The Center for Science in the Public Interest welcomed the move by Kraft to remove the dyes.

"I'm very pleased that Kraft is removing Yellow 5 and Yellow 6 from three particularly kid-friendly varieties of macaroni and cheese," said CSPI executive director Michael F. Jacobson. "That should be big help for kids - and their families and classmates - because those synthetic dyes promote hyperactivity and other behaviour problems in some children and may even pose a cancer risk."

Jacobson, however, urged parents to continue signing Hari's petitions on Change.org.

"As long as the Food and Drug Administration remains perched up in the bleachers and not on the playing field, action on the part of consumers is the only thing that will get these companies' attention."