adjacent colors, similar colors

Quick answer：

Adjacent colors and similar colors are both terms used in the field of color theory. Adjacent colors refer to colors that are next to each other on the color wheel, sharing a common color trait. Similar colors, also known as analogous colors, are colors that are close to each other in hue and are often found next to each other on the color wheel. These color relationships are important in design, art, and other creative fields as they can create harmonious and aesthetically pleasing color combinations.