A color model is a system for describing color as numbers so software can store, edit and reproduce it consistently. The two you will meet most often are RGB, which mixes red, green and blue light for screens, and CMYK, which mixes inks for print. Each model defines its colors in its own way, suited to how that medium physically produces color.
A helpful way to picture it is two different recipe books for the same dish. RGB is the recipe a screen follows by adding light, while CMYK is the recipe a printer follows by adding ink. Both can make “blue”, but they reach it through opposite methods, and neither can perfectly match every color the other produces. That gap is why a design can shift slightly when it moves from monitor to paper.
There are other models too, such as HSL, which describes color by hue, saturation and lightness and is friendlier for humans tweaking a shade by eye. Want a slightly lighter blue? In HSL you raise one number. In RGB you would juggle all three. Whichever model you work in, the actual value usually ends up stored as a color code that tools can read and convert. Each model also has a gamut, the full range of colors it can actually produce. RGB on a good screen covers a wide gamut, while CMYK on paper covers a narrower one. That mismatch is the practical reason a bright web blue can dull on a flyer. The colors outside the printer’s range get clamped to the closest match it can mix, and the design loses a little punch.
At TopDevs we set up client brand colors in the right model for each channel from the start, so the same design holds up whether it ships to a browser or a print shop.
