According to the Copyright Act, 1978 (as amended), § 12 (8) (a), "No copyright shall subsist in official texts of a legislative, administrative or legal nature, or in official translations of such texts; or in speeches of a political nature or in speeches delivered in the course of legal proceedings, or in news of the day that are mere items of press information."
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
This image shows a flag, a coat of arms, a seal or some other official insignia. The use of such symbols is restricted in many countries. These restrictions are independent of the copyright status.
Partially revert the change. See some images at https://www.thesouthafrican.com/news/people-were-invited-to-walk-over-the-old-flag-at-woordfees-in-stellenbosch/, https://www.voices360.com/politics/oranje-blanje-blou-against-the-backdrop-of-anti-racism-week-13852284
Adjust the size of three small flags, for example, the Orange Free State flag retains 2:3 ratio, but the height is half of the white stripe of main flag. See South Africa - National 1928-1994 - sheet 1.pdf