These primary colors are used in printing:
- Cyan-Cyan
- Magenta-Galibarda
- Yellow-Yellow
- Key-Black
Other intermediate colors are obtained by mixing these primary colors in required proportions. These colors are called CMYK because of the initials of the colors. The reason why the “B” of “black” is not used for the color black is that this color is preferred as the key color.
Editions prior to the 1970s only used CMY, so there was no black.
Because black was made from a mixture of CMY. Since this color was used too much in prints such as newspapers and magazines, the process of obtaining the color was taking too long and increasing costs.
For this reason, black was added to the CMY color space later on and revolutionized printing technology. Thus, both printing times were shortened and costs were reduced.
Thanks to this palette used, color output is controlled.
The juxtaposition of these circles indicates that all four colors were printed on top of each other without shifting, meaning that the printing was successful. If one of the four colors shifts, there will be ghosting and shifting in letters and images.
Unlike newspapers, the color palette used in packaging is wider.
7 different colors can be used instead of 4.
The purpose of the colors at the bottom of the toothpaste tubes is different.
In the frequently shared erroneous information on social media, it is said that these colors provide information about the content of the toothpaste, but the situation has nothing to do with it. These colors transmit to the light sensors where the bottom of the tube is. In this way, the toothpaste tubes are cut and closed correctly.
Sources: 1, 2