The textile industry is one of the main industries for ingestion of both surface and groundwater, along with the usage of chemicals and synthetic dyes. Numerous initiatives attempted to address the most popular synthetic dyes’ sustainability concern, where investigations have discovered cationization-based, salt-free reactive dyeing, process alternation by using polyacrylonitrile, cationic acrylic polymer, methylamine, trisodium nitrilotriacetate (TNA), etc. Many of the chemicals used to create cationic sites in cotton are neither eco-friendly nor sustainable. Nevertheless, all the alteration or critical process adaptation options could not open a real cost-effective, energy-saving, and eco-friendly window. In this context, researchers investigated less chemical-consumed pretreatment and even chemical-free pretreatment on cotton knit fabric. According to their research, chemical-free pretreated cotton has a higher dye uptake capacity than conventionally pretreated ones. This can be a hint for higher dye uptake by the cotton fabric. Auto-ionization can assist cellulose in turning into cellulosate ions (Cell-O-), which then can react with the reactive dye cation (C+). By dint of this encouraging hint, the present work was carried out by applying bi-functional reactive dye to chemical-free pretreated cotton knit fabric where the auxiliaries were not present. A significant level of depth of shade (K/S ≈ 2.0) was achieved for 3% shade; then four to five times repeated dyeing was also conducted for the maximum dye pick up as a whole by the fabric. The colorfastness to wash rating was almost 4–4/5 for all the cases. Fourier transform infrared (FTIR) investigation indicated no deviation from the conventional reactive dye-fiber bonding. The detailed Commission Internationale de l’Éclairage (CIE) Lab values along with Color Measurement Committee (CMC) Delta E (DE) color differences were revealed.