The flag of Guinea-Bissau consists of three horizontal stripes of equal size, with the top and bottom stripes colored yellow, and the middle stripe colored green. Centered on the green stripe is a black five-pointed star that is slightly larger than the width of each stripe. The aspect ratio of the flag is 1:2 (height to width), and its geometric properties are rectangular with a length of 200 units and a width of 100 units. The official color codes for the flag are:

• Yellow: Pantone 116 C (#FCD116)
• Green: Pantone 356 C (#007A3D)
• Black: Pantone Black C (#000000)