An activist investor is leading the charge in calling on WK Kellogg Co to uphold a previous pledge to remove several food dyes from cereals like Froot Loops and Apple Jacks. Jason Karp — a WK Kellogg Co shareholder, as well as the founder and CEO of holding company HumanCo which invests in better-for-you food and beverage brands — led a protest at the cereal company’s headquarters in Battle Creek, Michigan, on Tuesday. The demonstrators demanded Kellogg remove several dyes that can still be found on the ingredient decks of its cereals.