**Hex** colour codes are a compact six-digit hexadecimal notation of RGB values, in the form #RRGGBB. Each pair of characters expresses one channel in the range 00-FF. Hex is the standard format for specifying colours in web design and is therefore the most common digital expression of flag tinctures on the open web.
**Example**: The deep blue of the flag of the United Nations is commonly given as #5B92E5 in web specifications.
**See also**: [rgb](/glossary/rgb/), [cmyk](/glossary/cmyk/), [pantone](/glossary/pantone/), [construction-sheet](/glossary/construction-sheet/)