Cameroon flag is defined in the Law #96/06 of 18 January 1996 Constitution of Cameroon on Part (1) one "The State and Sovereignty" Article (1) one paragraph (5) as:
... (5) Cameroon flag shall be three equal vertical stripes of green, red and yellow charged with one gold star in the centre of the red stripe...
The flag of Cameroon adopts the popular pan-African colors (with Cameroon being second to Ghana); Green, Red and Yellow with a five-pointed yellow star at the center of the red band. This is the official flag of Cameroon from 20th May 1975 to present.
The Federal Republic of Cameroon 1st October 1961 to 20th May 1975 had a two star Flag in the Green band representing the two states (British Cameroon and French Cameroun).
The Cameroonian flag of 1957 to 1961 was a simple unadorned tricolor flag composed of the Pan-African colors: Green, Red and Yellow.
The Green stands for Hope, the green vegetation, rich forest of the south and hope for a happy future
The red: stands for unity and independence, national sovereignty.
The star : the unity of Cameroon
The Yellow for the Sun - source of happiness and prosperity and also the northern savannas
The Cameroonian flag is based on the Ethiopian flag of 1897 but style to the French vertical tricolor.
1884 - 1919: Cameroon (Kamerun) is a German colony.
199 - 1957: Cameroon is administered Britain (20%) and the french (80%) under the Trusteeship of the League of Nations.
1957 French grants autonomy to french cameroon and the first Cameroon flag is hoisted, having an unadorned vertical green, red, yell bands.
November 2nd 1961 British and French Cameroon unite as a federation. The second Cameroon national flag is formed and hoisted in Buea (Capital of German Kamerun and British Cameroon) consisting of three bands of Green, Red and Yellow with two golden color stars in the Green, each star for each state.
20th May 1975 following the unification of the two federal states of Cameroon into one unity system, the Cameroonian flag was once again changed to a three vertical band with green , red and yellow pan-african colors and a single yellow star in the center.