Midnight blue is a dark shade of blue named for its resemblance to the identifiably blue color of a moonlit night sky on or near the night of a full moon. Midnight blue is the color of a vat full of Indigo dye; therefore, midnight blue may also be considered a dark shade of indigo. Midnight blue is identifiably blue to the eye in sun-light or full-spectrum light, but can appear black under certain more limited spectrums sometimes found in artificial lighting (especially early 20th century incandescent). It is similar to navy, which is a also a dark blue.