Final answer:
Analogous colors, such as red and orange or blue and green, are next to each other on the color wheel and blend smoothly due to their similar wavelengths, creating a harmonious visual effect.
Step-by-step explanation:
Colors that do not contrast strongly with each other and which are similar in wavelength are known as analogous colors. Analogous colors are positioned next to each other on the color wheel and they blend smoothly because the light waves they reflect or emit are more similar in wavelengths. This often creates a harmonious and calm visual effect, as opposed to complementary colors, which are located directly opposite each other on the color wheel and offer a bold contrast. For instance, red and orange are analogous, just as blue and green are, and they are often found in works that require a soothing and less visually active composition.