The flag that is red, yellow, and green is used by several countries. Here are some of them:

• Bolivia: The flag has three horizontal stripes of equal size, with red at the top, yellow in the middle, and green at the bottom.
• Ethiopia: The flag has three horizontal stripes of equal size, with green at the top, yellow in the middle, and red at the bottom.
• Ghana: The flag has three horizontal stripes of equal size, with red at the top, yellow in the middle, and green at the bottom.
• Guinea: The flag has three vertical stripes of equal size, with red on the left, yellow in the middle, and green on the right.
• Mali: The flag has three vertical stripes of equal size, with green on the left, yellow in the middle, and red on the right.
• Republic of Congo: The flag has three sections, with a green upper triangle, a yellow diagonal band that splits the flag in half from the hoist’s bottom corner, and a red lower triangle.
• Senegal: The flag has three vertical stripes of equal size, with green on the left, yellow in the middle, and red on the right.

Therefore, the flag that is red, yellow, and green could belong to any of these countries.