Why do colours look different on print than on my screen?

Screens use the RGB (Red, Green, Blue) additive colour model, which can display vibrant, glowing and neon hues. Printing uses the CMYK (Cyan, Magenta, Yellow, Black) subtractive model, which relies on physical inks reflecting light and has a slightly narrower range. So bright screen colours may look slightly more muted or deeper when printed.