<Tr> <Td> Blue </Td> <Td> CKS 762 c National flag blue </Td> <Td> Reflex blue c </Td> <Td> #0C1C8C </Td> <Td> </Td> </Tr> <P> The Anglo - Boer War between 1899 and 1902 ended with the Treaty of Vereeniging on 31 May 1902 and resulted in what is now South Africa falling under the British Union Flag . The former Boer Republics of the Orange Free State and the Zuid - Afrikaanse Republiek (Transvaal) became British colonies along with the existing Cape and Natal colonies . Each was also entitled to a colonial flag following in the British tradition . </P> <P> On 31 May 1910 these four colonies came together to form the Union of South Africa and the individual colonial flags were no longer used and new South African flags came into being . Once again, as a British dominion the British Union Flag was to continue as the national flag and the standard British ensign pattern was used as a basis for distinctive South African flags . </P> <P> As was the case throughout the British Empire, the Red and Blue Ensigns were the official flags for merchant and government vessels at sea, and the British Admiralty authorised them to be defaced in the fly with the shield from the South African coat of arms . These ensigns were not intended to be used as the Union's national flag, although they were used by some people as such . Although these ensigns were primarily intended for maritime use, they were also flown on land . </P>

When was the new national flag of the republic of south africa hoisted on