Websites with similar colors often use a color scheme that is harmonious and pleasing to the eye. This can be achieved by using a combination of colors that complement each other or by using shades and tints of a primary color. A color scheme can also be designed to evoke certain emotions or convey a particular brand identity. To find websites with similar colors, you can use online color schemes generators, website analyzers, or simply observe the color palettes of sites you find visually appealing.