Where in the world?
The flag of Guinea has three vertical stripes of red, yellow, and green.

Guinea

Guinée

Population: 13,132,792

Region: Africa

Subregion: Western Africa

Capital: Conakry

Top Level Domain: .gn

Currencies: Guinean franc

Border countries

The flag of Ivory Coast has three vertical stripes of orange, white, and green.

Ivory Coast

Population: 26,378,275

Region: Africa

Capital: Yamoussoukro
The flag of Guinea-Bissau has two horizontal stripes of yellow and green, with a red vertical stripe on the hoist side containing a black star.

Guinea-Bissau

Population: 1,967,998

Region: Africa

Capital: Bissau
The flag of Liberia has eleven horizontal stripes of red and white, with a blue square in the upper hoist-side corner containing a white five-pointed star.

Liberia

Population: 5,057,677

Region: Africa

Capital: Monrovia
The flag of Mali has three vertical stripes of green, yellow, and red.

Mali

Population: 20,250,834

Region: Africa

Capital: Bamako
The flag of Senegal has a green, yellow, and red vertical tricolor with a green star in the center.

Senegal

Population: 16,743,930

Region: Africa

Capital: Dakar
The flag of Sierra Leone has three horizontal stripes of green, white, and blue.

Sierra Leone

Population: 7,976,985

Region: Africa

Capital: Freetown