Combination of yellow and red in flat design

Quick answer：

The combination of yellow and red in flat design often evokes a vibrant and energetic vibe. Yellow, being a warm color, can convey happiness and optimism, while red, a warm color, is often associated with passion and energy. In flat design, these colors are used in a balanced way to create a visually appealing and harmonious design. It is important to consider the color psychology and the context of the design to ensure the combination is effective and pleasing to the eye.