Bacteria in dental and oral diseases can lead to systemic issues like kidney and heart disease, emphasizing the importance of maintaining oral hygiene. Disclosing solution, a plaque-revealing agent, is pivotal in assessing plaque removal efficacy. The optimal concentration of rose pink food coloring for plaque visibility is 2.5 g/20 ml water. However, the potential impact of this coloring on oral epithelium remains unstudied. Objective: This research aimed to evaluate the effect of disclosing solution food coloring on the gingival mucosal layer in mice. Pure experimental research with a control group design involved 6 mice (Mus musculus) each in treatment and control groups. Erythrocyn, derived from rose pink food coloring, was applied to mice’s gingiva for 2 minutes daily over 7 days. Labio-gingival epithelial cells were then sampled and analyzed using the modified Feulgen-Roseenbeck method. 58.33% of mice showed karyolysis in gingival epithelial cells, contrasting with no karyolysis in lip mucosa. Careful management of food coloring-containing erythrosine as a plaque detection agent is crucial to prevent contact with oral mucosa or prompt cleaning if contact occurs.