Are the colored additives used in Kraft's popular Macaroni & Cheese products dangerous? That's what two food bloggers are alleging in their petition to Kraft Foods to remove Yellow No. 5 and Yellow No. 6 from the blue-boxed pantry staples. Yellow Nos. 5 and 6 are used to color beverages, dessert powders, candy, ice cream, custards and other foods. Vani Hari, from the blog Food Babe, and Lisa Leake, from 100 Days of Real Food, have taken to Change.org to petition Kraft's management to remove the dyes, saying they may potentially cause health problems and are not included in Kraft's Mac & Cheese products sold in the United Kingdom. "Kraft reformulated their product for the UK, but not for their fellow American citizens," they argued. At press time, the petition had nearly 135,000 signatures. The Center for Science in the Public Interest, a consumer advocacy group, has been petitioning to ban food dyes in the U.S. for years. In a 2010 report called Food Dyes: A Rainbow of Risks, the CSPI says Yellow Nos. 5 and 6 can cause hypersensitivity, or allergic reactions, and contain carcinogens called Benzidine and 4-amino-biphenyl. Some studies reported hyperactivity in children associated with Yellow 5 intake or genotoxicity -- or damage to cellular DNA -- says CSPI. Yellow 5 is the most widely used food dye after Red 40, according to CSPI.