Colour management is the controlled conversion between the colour representations of different devices you use, such as digital cameras, monitors, and printers.
Colour management helps you to achieve the same colour appearance on all of the different devices you use, provided those different devices are all capable of delivering the necessary colour intensities.
Historically, printing was managed using the CMYK Color Mode. So any image file would routinely be converted into CMYK as a starting point for preparing it for printing in carefully constructed mixtures of Cyan, Magenta, Yellow and Black inks to match known colour swatches, for example the Pantone series.
However, digital printing works differently. With digital printing you can choose as many as you want of a huge range of colours, at no extra cost or effort, and these colours are mixed up automatically as printing progresses.
When you are digitally printing, it is best to work in the RGB colour mode; if you convert to CMYK mode you are likely to lose valuable colour information from your image, because the CMYK colour space is smaller than the RGB colour space.
In colour management, an ICC profile is a set of data that characterizes a colour space according to standards set by the International Color Consortium (ICC).
Images from cameras, images on the web, computer screens, and so on, most commonly use the sRGB colour profile. However, the sRGB colour space is able to represent fewer colours than can the Adobe RGB (1998) colour space, or the ProPhoto colour space. If you are just working with images to be displayed on screen, it is best to leave those images to use the sRGB colour profile. However, when you are designing for print, using the sRGB colour profile will generally not produce the best outcome.
The diagram below shows that the Adobe RGB 1998 colour space encompasses a much wider range of colours than does the SRGB colour space that most images use by default.
In this diagram, the coloured horshoe-shpaed area represents visible colour, and the triangles inside it represent the range of colours within each colour space. It can be seen that more colours, especially at the blue/green end, are included in the Adobe RGB (1998) colour space than are included in the sRGB colour space. ProPhoto colour is another option, but you can see here that it extends beyond visible colour space, so choosing that profile can cause other problems that are hard to deal with, because it includes colours that we are not actually able to see.
We use the Adobe RGB (1998) colour profile when we print your image, so to get the best idea of your colour outcome when printing with us, it is best for you to design using this colour profile, also.