Klein blue is a kind of blue, which is also called sapphire blue because it is similar to pure sapphire. Chromatographically, it is pure blue, with pure tone and pearlescent luster, so it is a kind of pearlescent color system and belongs to cool tone.
The RGB ratio of "Klein Blue" is 0: 47: 167, which is a blue named after the artist Klein, that is, the so-called absolute blue. Because there is a strong conflict with the environmental color in visual contrast, it can especially reflect the sense of self-existence. Klein believes that expressing a feeling requires neither explanation nor language, and only the purest color can arouse the strongest spiritual sensibility.
Eight drawing boards of the same size, painted with almost ultramarine pigments, appeared at the Milan Art Exhibition 57 years ago, which was the birth of Klein Blue. Ultramarine, which means "from far away overseas" in Italian, originally refers to several imported goods, not just pigments. This color is made of lapis lazuli.