The flag of São Tomé and Príncipe consists of three horizontal stripes, with the top and bottom stripes being green, and the middle stripe being yellow. On the left side of the flag, there is a red isosceles triangle that extends to the center of the flag, with two black five-pointed stars placed at the triangle's base. The flag has an aspect ratio of 1:2, and its geometric properties include a rectangle shape with dimensions of 1 meter by 2 meters. The color codes for the flag are:

• Green: Pantone 355 C / RGB 0, 147, 70
• Yellow: Pantone 116 C / RGB 255, 204, 0
• Red: Pantone 485 C / RGB 206, 17, 38
• Black: Pantone Black C / RGB 0, 0, 0

Note that these color codes may vary slightly depending on the source.