This study aimed to develop a natural colorimetric aerogel based on carboxymethyl cellulose (CMC), sodium alginate (SA), black goji anthocyanin (BGA), and various natural fibers such as cotton fiber (CF), silk fiber (SF), and down fiber (DF) via a combined approach of ionic gelation and freeze drying for monitoring fish freshness. Various colorimetric aerogels, (CMC/SA, CMC/SA/CF, CMC/SA/SF, and CMC/SA/DF) were developed and analyzed. Among them, CMC/SA aerogel showed higher density (0.054 g/cm