27 April 1994
On 27 April 1994, South Africa introduced a new national flag, at the same time the country held its first democratic elections in which African National Congress  (ANC) won. Nelson Mandela became the first democratic president. It replaced the previous national flag which had flown over South Africa since 31 May 1928 until just before midnight on 26 April 1994.The national flag first flew on 10 May 1994 when Mandela was inaugurated as the president. Frederick G. Brownell Source:www.bbc.com The flag is made up of six colours: chilli red, white, spectrum green, blue, black and yellow represent a symbol of the unity of the different race groups in South Africa. The flag was designed by Frederick G. Brownell, from theState Herald of the Republic of South Africa. Initially, members of the public and design studios were asked to submit their ideas and about 7,000 sketches were submitted.  However,  the Negotiating Council, who had appointed the National Symbols Commission, and the public did not find any that were suitable. 
References

South Africa History Online. South African National Symbols and Heritage. [online] Available at  www.sahistory.org.za [Accessed 21 October 2013]|BBC News Magazine., 2014. Fred Brownell: The man who made South Africa's flag. [online] Available at  www.bbc.com [Accessed 14 April 2014]