Three colors with good color matching

Quick answer：

The question refers to color schemes that are aesthetically pleasing. In design and art, a color scheme is a predefined set of colors used in a particular context. Aesthetically pleasing color schemes often follow principles such as complementary colors, analogous colors, or monochromatic schemes. Complementary colors are pairs of colors that, when combined, cancel each other out (e.g., red and green, blue and orange). Analogous colors are those that are next to each other on the color wheel and create a harmonious blend (e.g., red, orange, and yellow). Monochromatic schemes use different shades of a single color, which can also be visually pleasing.