The leopard coral grouper (Plectropomus leopardus) is one of the most economically important species of grouper in Asia, particularly the wide-type individuals with a bright red color that are typically found in tropical and subtropical coral reef habitats. Improvements in fishing technology and increasing market demand have resulted in a rapid decline in the population of wild-type leopard coral groupers. To maintain this population of groupers, an artificial propagation technique has been successfully developed by the Fisheries Research Institute. However, the skin of these fish often lacks the bright red coloration, which does not meet the needs of the market enough to alleviate overfishing. The mechanisms underlying the coloration of the leopard coral grouper remain unknown. This study collected 2,916 related data from wild-type leopard coral groupers with different skin colors across ten Penghu sea areas, and their deposited their genomic DNA for further examination. The data showed that the body length of the bright red individuals was significantly larger than that of the brown and red-brown individuals. Contemporary genomics methods and linear mixed model analysis were utilized, and the results showed three single nucleotide polymorphisms (SNPs) associated with color-associated quantitative trait loci (QTLs). SNP_87_4 was significantly associated with the coloration of multiple body positions in leopard coral groupers. In conclusion, this study may help select the redness color leopard coral grouper for brood stock, and consequently to satisfy market demand for bright red individuals. Thus, overfishing of the wide-type individuals would decrease, and a balance between fishing and conservation would be maintained.