This study reported a facile structural modification of cellulosic fabric (cotton) by applying two different polyphenol enriched extracts derived from the banana floral stem (BFS) and watermelon rind (WR) for imparting UV protective functionality. The dye extracts are comprised of various UV protective natural chromophores (UVPNCs) such as tannin, flavonoids, anthraquinone, anthocyanin, betacyanine. The concentrations and absorbance intensities of UVPNCs were confirmed by phytochemical screening and UV spectroscopy. Better absorption behavior for BFS and WR chromophores into cellulose was found at 80°C and 60°C temperature with a constant runtime of 60 minutes. At this conditions, the fixation rate of BFS and WR was 53-63% and 25–85%, respectively. Furthermore, cellulose substrates were chelated with different types of metals (Al3+, Sn2+, Fe2+, and Cu2+) to promote the chromophore fixation. The effect of metal chelation with cellulose chain was estimated in terms of crystallinity indices, hydrogen bonding configurations and asymmetric factor, which were correlated with the enhanced UVPNCs fixation. The higher amount of BFS and WR chromophores were absorbed for Fe2+ and Cu2+, demonstrating ~61% and ~ 26% improvement in color strength (K/S), respectively. The formation of UVPNCs-metal-cellulose complex, decreased the UV transmission rate of the BFS and WR dyed fabrics. Interestingly, BFS dyed substrate exhibited higher (UPF = 50+) UV shielding ability compared to WR dyed substrate (UPF = 4.20) due to higher UVPNCs absorbance intensities and bonding capacity of BFS extract. Finally, the durability of functionality of BFS and WR dyed substrates was confirmed in terms of various colorfastness.