What is a “color space”?


What the hell is “color space”. Many people are wondering about this and at the same time quietly bent over not understanding and needing it at the same time. So what are all these descriptions and labels – Adobe RGB, sRGB, ICC,…? In short, these are numerical records that determine the values of each color, ie standards. Since usually all devices (monitor, printer, digital camera…) show a different picture, some standard is absolutely necessary.

It should also be understood that not all of these devices are equally capable of displaying colors. Not to mention the multitude of different manufacturers and the confusion is even greater. Due to its technology, the monitor already has problems displaying some theoretically defined colors, not to mention printers. Let us leave aside the fact that each eye has its own painter. So we need a standard that combines this – equipment developed at hundreds of different ends.



A good 15 years ago, Microsoft and HP set themselves the task of fixing things up a bit. Hand on heart – these things Adobe had already arranged, but their sinfully expensive products were primarily the domain of professional studios, where they were dedicated to preparing for printing on Apple machines. Now, however, everything has become more widely available (unfortunately also with a lack of knowledge). Well, anyway, a new standard has emerged – sRGB, which every digital camera has today, some better, especially mirror-reflex, and a little more extensive Adobe RGB.

Območja, ki ga pokrivajo različni barvni prostori.


Areas covered by different color spaces / records.
We see how the space for printing in the CMYK technique is limited due to the display technology.


How we hunt a green rabbit.

So how do you best prepare image files? Depends of course on what we will need them for. For most needs, sRGB color space is sufficient, which describes the colors very well, only in blue-green shades it is a bit “carried” by Adobe RGB. We can use it everywhere, especially in online displays, because most browsers do not understand a different model and in the case of Adobe RGB it shows us washed colors. Color spaces can also be set / converted in Photoshop. However, we need to know that most printers only understand sRGB and it is better to leave photos in this basic format for average use. If we are going to play with the conversion to Adobe RGB in the hope that we will get more shades from the photo, we are seriously mistaken here. Namely, certain information is basically NOT there and no conversion conjures it up. With inappropriate conversion, we will at most “cut” the part that is rich in information. Printed photos will be faded and washed out.

Numeric values are therefore moved higher and a simple printer does not understand this. He can’t be blamed. It behaves according to the most widespread standard – like the previously mentioned web browsers. If we have already captured or received the image in Adobe RGB, we simply convert it to sRGB and the printout will be beautiful again. Something else, however, are professional typewriters and illuminators that use RIP technology. There, the file is taken over by controllers, which are described as ICC descriptions and are adapted to each machine individually. Then it makes sense to capture in Adobe RGB, because we will convert it into an ICC description and because we need as few losses as possible – so we use a color space that will give the description as wide a range of shades. This also applies to the choice of colors for, say, a corporate graphic image . It is wise to choose such a set of colors that the screen and printed display will be as uniform and realistic as possible.

CMYK color space

It’s not really a color space, but a simulation of shades by mixing 4 colors. It is used in offset printing and has a much smaller color gamut than the aforementioned RGBs. In particular, more vibrant colors such as bright green and bright orange are making it a problem. Here, too, it is true that for optimal results, we should in principle know the machine on which the printed matter will be produced, because in this case we develop the image in the ICC model of this particular machine. This would make the most of its ability to display correctly and desired on paper. Of course, provided that strict rules apply to lighting and printing and the whole process is controlled.

One more piece of advice – we must always store the image material in RGB files, only when using it for printing do we make a CMYK copy. When converting to a smaller color space, certain information is lost forever and there is no going back. So we caught a rabbit.

More on this topic will be in one of the next posts, where I will address the human perception of color and how colors are created.