We consume fruits and vegetables every day without knowing whether or not agricultural residues (i.e. pesticides & heavy metals) are present. In 2017, according to the UN, exposure to pesticides caused 200,000 to 300,000 deaths annually. Additionally, lead exposure alone is responsible for a death rate of 25.3 per 100,000 individuals in East Asia. Current methods of agricultural residue detection are not easily accessible to the public and are inconvenient for everyday use. Thus, our project aims to allow for convenient visualization of agricultural residues by designing colored proteins that can directly interact with these residues. We envision a system where our designed proteins can be applied directly on food items to detect the presence of residues. Our final product can be used by consumers, distributors and farmers alike.