Okla. Stat. tit. 47, § 12-428
School buses converted for purposes other than transporting pupils to or from school shall be painted a color other than national glossy yellow. The loading lights shall be disconnected, except for buses purchased for use by religious organizations as defined in Section 1 of this act.
Laws 1973, c. 112, § 6; Laws 1974, c. 57, § 1; Laws 1978, c. 262, § 2, eff. Oct. 1, 1978.