Purpose: To determine the effect of potassium iodide (KI) on the black/gray staining caused by silver diammine fluoride (SDF) when applied to carious lesions. Methods: Extracted caries-free molar surfaces had caries induced to examine the use of SDF and SDF followed by KI (SDF+KI) on extracted permanent molars that had caries induced on their surfaces and were monitored for a period after application. To monitor the color changes, CIELAB color space readings???a color space defined by the International Commission on Illumination???were used. The system is composed of three values, of which the L* measures black to white across a span of zero (black) to 100 (white). Measurements were taken at eight intervals between days zero to 72. Results: L* values were found to be significantly different between SDF and SDF+KI groups and from baseline. On average, the SDF+KI group versus the SDF group was 9.47 units lighter. Conclusion: The findings indicate the application of silver diammine fluoride followed by potassium iodide can reduce the black staining SDF alone causes, potentially making it a viable esthetic option for patients with anterior tooth caries.