Colors you see on screen will look differently to colors that have been printed out.
Colors on screen are based on the RGB color system. These colors are created by mixing 3 colors of light beams together - red, green, blue. RGB colors can only be displayed digitally on screens (e.g. computer monitors, smartphones) because they are made with light.
Colors in print are usually based on the CMYK color system. These are process colors that are created by mixing 4 colors of ink together - cyan, magenta, yellow, and key (black). These are the exact same colors as the ink cartridges in your home or office printer!
In addition to CMYK, another popular color system is called PMS (Pantone Matching System) - or simply Pantone for short. These are spot colors and are pre-mixed ink that's primarily used for very specific brand colors (e.g. Tiffany's blue), and for colors that are difficult to create using CMYK (e.g. very bright colors, metallic colors). Pantone colors are more expensive than CMYK, and are ideal if you need consistent and accurate colors for every print run.