Multifunctional cotton fabric with adjustable color was simply fabricated by anchoring solid solution BiOBrxI1−x nanosheets on the surface of carboxymethylated cotton fabric for self-cleaning, UV protection, and near infrared reflection. The structure and morphology of prepared multifunctional cotton fabrics (BiOBrxI1−x-CCF (0 ≤ x ≤ 1)) were characterized by X-ray powder diffraction and scanning electron microscopy. Color, self-cleaning, UV protection, near infrared reflection, and acid and alkali resistance of these multifunctional cotton fabrics were systematically studied. With the increase of iodine content, the BiOBrxI1−x nanosheets with an average thickness of 40–50 nm and a size of 1–2 μm in the other two dimensions loaded on the cotton fabrics can extend the absorption edge of BiOBrxI1−x-CCF (0 ≤ x ≤ 1) from 430 nm to 630 nm, giving cotton fabric color and excellent UV protection property. Interlaced solid solution nanosheets on cotton fabric surface give BiOBrxI1−x-CCF hydrophobicity (contact angle: 139°–143°) and ability to photodegrade stain under the visible light irradiation. The near infrared reflectance of BiOBrxI1−x-CCF (0 ≤ x ≤ 1) is higher than that of the raw cotton, which gives it infrared reflection thermal isolation. BiOBrxI1−x-CCF (0 ≤ x ≤ 1) has a certain acid and alkali resistance in solution (pH 2.3–11.2). Thus, BiOBrxI1−x-CCF has great potential to be used as multifunctional fabric in self-cleaning and outdoor protection.