International Klein Blue (IKB)

Yves Klein’s famous blue colour International Klein Blue (IKB) is subject to copywriting, and its precise composition remains shrouded in mystery. Michael Skalka’s essay on the subject explains what is known about the colour (Skalka, 2024). An approximation can be achieved for my printing purposes by combining pigments according to published colour specifications.

Hexadecimal is a 16-digit code most commonly used in the computing industry. The digits range from 0 through the decimal range to 9 and then through letters a-f.  Hexadecimal is often used to express binary numbers in a shorter format.  Binary 0000 is equal to 0 in Hexadecimal, Binary 00101111 equals 2f and Binary 11111111 equals ff.

Each two-digit hex code represents a decimal number from 0 to 255. Therefore the full hex colour code can represent over 16 million different colours.

IKB has a hex colour code of #002fa7 which refers to an RGB colour value

Element 1: Red value =   00 = 00000000 binary = 0 decimal

Element 2: Green value  2f = 00101111 binary = 47 decimal

Element 3: Blue value    a7 = 10100111 binary = 167 decimal

But for printing the Hex colour value needs to be expressed as CMYK. This conversion is more complicated, so I have taken the values below from ColorHexa.com as accurate. according to colorhex.com, the RGB values can be recreated using CMYK pigments in the following ratio:

100% cyan

71.9% magenta

0% yellow

34.5% black

The ratios can be measured using basic weighing scales. Starting with a fixed weight of Cyan ink, the other colours can be calculated as a proportion of the cyan weight and added to the mix. For screen printing a transparent base needs to be added to the mixed inks at a ratio of 50/50.

COLORHEXA, n.d. #002fa7 Color Information [Viewed 10/11/2024]. Available from: https://www.colorhexa.com/002fa7 

ISTOCK STAFF, 2023. The Ultimate Guide to Hex Colors [Viewed 10/11/2024]. Available from: https://www.istockphoto.com/blog/best-practices/design/hex-colors-guide#:~:text=0%20to%20255.-,A%20hex%20color%20code%20is%20a%206%E2%80%91symbol%20code%20made,value%20from%200%20to%20255.&text=The%20code%20is%20written%20using,unique%202%E2%80%91digit%20alphanumeric%20code.

SKALKA, M., 2024. International Klein Blue [Viewed 10/11/2024]. Available from: https://www.syntaxofcolor.com/post/international-kline-blue-pigment