NOVELTY - A cosmetic composition comprises: an organosilane compound (A); and at least one cosmetic ingredient (B).    USE - As cosmetic composition for hydrating skin, coloring keratinous fibers, maintaining color to keratinous fibers, and reducing frizzing of keratinous fibers (claimed).    ADVANTAGE - The cosmetic composition applied on hair provides benefits including hair conditioning, softness, detangling ease, silicone deposition, anti-static, anti-frizz, lubricity, shine, strengthening, viscosity, tactile, wet combing, dry combing, improvement in coloration process, color retention, straightening, heat protection, styling, or curl retention.    DETAILED DESCRIPTION - A cosmetic composition comprises: an organosilane compound of formula (R1)(3-n)(R2O)nSiR3O(CH2CH2O)a(C3H6O)bR4 (A); and at least one cosmetic ingredient (B).    n=1-3;    a= greater than or equal to 1;    b=0-30;    R1=1-12C hydrocarbon;    R2=H o 1-6C alkyl;    R3=2-12C divalent hydrocarbon;    R4=H, R1, or acetyl.    Provided that a is greater than or equal to b. INDEPENDENT CLAIMS are included for the following:    (1) a process of hydrating skin involving: mixing the organosilane compound (A) with the cosmetic ingredient (B); applying it to the skin; and optionally rinsing the skin;    (2) a process of coloring keratinous fibers involving: mixing the organosilane compound (A) with the cosmetic ingredient (B) selected from hair dyes, hair colorants; applying the mixture to the keratinous fibers; and optionally let the mixture stand on the keratinous fibers; and optionally rinsing the keratinous fibers;    (3) a process of maintaining color to keratinous fibers involving: mixing the organosilane compound (A) with the cosmetic ingredient (B) selected from surfactants, hair dyes, hair colorants; applying the mixture to the keratinous fibers, optionally let the mixture stand on the keratinous fibers, and optionally rinsing the keratinous fibers; and    (4) a process of reducing frizzing of keratinous fibers involves: mixing the organosilane compound (A) with water; applying the mixture to the keratinous fibers; optionally letting the mixture stand on the keratinous fibers, and optionally rinsing the keratinous fibers.