What color is most likely to make red stand out when used together?

The most effective color to make red stand out when used together is green. This is primarily due to the way colors interact with one another on the color wheel. Green and red are complementary colors, meaning they are located opposite each other. When placed side by side, complementary colors enhance each other's brightness and intensity, making red appear more vivid and striking against the backdrop of green.

The visual contrast created between these two colors makes red pop, drawing the viewer's attention. In design and color theory, leveraging complementary colors is a common technique to achieve dynamic visuals and highlight specific hues. As a result, using green alongside red results in a strong visual impact, making red stand out effectively.