Retro color with blue refers to a color scheme that combines classic or vintage colors with shades of blue. This combination can be used in interior design, fashion, and art to create a nostalgic yet modern aesthetic. In interior design, retro colors like pastel shades or muted tones are paired with various shades of blue to evoke a sense of timelessness and relaxation. In fashion, the combination can range from subtle to bold, depending on the specific colors chosen.