Brown's adjacent colors or similar colors

Quick answer：

Adjacent colors, also known as analogous colors, refer to hues that are next to each other on the color wheel. For brown, its adjacent colors could be shades of red-brown, orange-brown, or yellow-brown. Similar colors, on the other hand, are those that are close in value and intensity but not necessarily next to each other on the color wheel. This concept is used in color theory to create harmonious color palettes.