blue and adjacent colors

Quick answer：

Adjacent colors refer to colors that are next to each other on the color wheel, sharing a common color trait. They include analogous colors, which are next to each other and have similar hue, and complementary colors, which are directly opposite each other on the color wheel and create a stark contrast. Blue, being a primary color, has various adjacent colors that range from similar shades of blue to hues like green, violet, or purple.