Deep blue is blue, it is the transition color between blue and black, it is deep blue and deep blue, its pigment and visual sense are lighter than black and darker than blue. Ink blue is generally divided into light ink blue and deep ink blue. Purple blue is similar to blue ink, and purple blue is similar to adding black ink to blue ink.

Dark blue generally refers to dark blue, which is relatively dark blue. Among them are sapphire blue, midnight blue and so on. Although these two colors belong to the category of blue, dark blue is slightly bluer than dark blue. Purple blue is similar to blue ink, and purple blue is similar to adding black ink to blue ink.