Red and blue color combination in flat design

Quick answer：

Red and blue color combinations in flat design often refer to the use of these colors together in a flat design aesthetic. Flat design is a style that emphasizes simplicity and minimalism, with no drop shadows or gradients. Red and blue can evoke a range of emotions and are often used to create contrast and highlight important elements in a design. This combination is popular in branding, digital interfaces, and graphic design, where it can convey energy and professionalism.