That two colors go well together

Quick answer：

This statement reflects an aesthetic preference in color theory. Color harmony is a fundamental concept in design, where certain colors are perceived as pleasing when combined. The concept of 'good color pairing' can be based on various color theories, such as complementary colors, analogous colors, or monochromatic schemes. To achieve a harmonious color combination, designers often consider the context, cultural associations, and the intended emotional response.