Fluoroalkyl end-capped 2-(methacryloyloxy)ethanesulfonic acid oligomer [RF-(MES) n -RF]/polyaniline (PAn) nanocomposites, which were prepared by the polymerization of aniline initiated by ammonium persulfate in the presence of the corresponding oligomer, can cause the smooth color change from green to wine-red (or purple), triggered by a variety of basic compounds such as ammonia, sodium hydroxide, 2-hydroxyethylamine, tris(hydroxymethyl)aminomethane, and silica particles bearing 3-aminopropyl groups (Amino-SiO2) under room temperature. It is found that the RF-(MES) n -RF/PAn nanocomposites undergo a change in the color when they are exposed to ammonia vapor, and especially, a good reversible color change from green to wine-red color through the chemochromic behavior is observed when they are under air and exposure to ammonia vapor. Purple-colored RF-(MES) n -RF/PAn/Amino-SiO2 blend hybrids powders, which are prepared by the interaction of RF-(MES) n -RF/PAn nanocomposites with Amino-SiO2 particles, can cause the solvatochromic response in water, methanol, chloroform, and fluorinated aliphatic solvent to give the color change from blue to colorless (white-gray) in the fluorinated solvent.