Yield signs are triangles with what color for the body?

Answer: A — Red

Yield signs use an inverted triangle with a red border and a white interior. The white interior is the body color, chosen for high visibility and to clearly indicate a regulatory instruction to slow down and yield to other traffic. The red border adds emphasis and aligns with the general warning/alert signaling, but the interior color remains white. So the body color is white. Red describes the border, while blue, green, and yellow are used for other sign purposes (informational, direction, or warning).