Underwater exploration has uncovered valuable resources, including minerals, energy sources, and unique marine life, with significant implications for industries, research, and conservation. However, with the influence of light absorption and scattering properties, underwater imagery often faces challenges such as color distortion, imbalance, low contrast, and color cast. The difficulties lie in whether the color cast removal will further extend the color distortion as different levels of color loss will deeply affect the consistency of the underwater image enhancement’s performance. This paper introduces a technique to enhance underwater image quality using a gray scale reference (GSR) approach to remove the color cast in the process of restoring and balancing colors. The proposed method combines the Gray World (GW) and generalized color compensation (GCC) principles for color balancing and enhances the image contrast with Mix-CLAHE. The results of the Underwater Image Quality Measure (UIQM) metric indicated the proposed gray scale reference method outperforms GW, GCC, and Mix-CLAHE, offering significant improvements in image quality and consistently removing color cast.