The company is the first major cereal company to replace those artificial ingredients with fruits, vegetables and spices.
Gallager provided an exclusive look at General Mills' top secret cereal lab where they tried hundreds of natural ingredients like tomatoes, purple carrots and spices like turmeric for colors.
Already, 60 percent of General Mills cereals don't use artificial colors and flavors, the company said, including Cheerios and several Chex products.
By this coming January, the company said 75 percent of its cereals will be without those artificial ingredients, likely including Trix and Reese's Puffs; and by the end of 2016, the company hopes to cover 90 percent of the cereal brands.
The biggest challenge for General Mills' goal will be cereal brands with marshmallows, including Lucky Charms. The company said those cereals will likely be the last ones to join the club by the end of 2017.