Hex Code (Hexadecimal Color Code)

A hex code, short for hexadecimal color code, is a way of writing an exact color as a short string of characters, most commonly in the form #RRGGBB. It describes a color by the intensity of its three light channels — red, green, and blue — with each channel given a two-character value. Those characters are hexadecimal, meaning base-16, so they use the digits 0 through 9 and then the letters A through F to count past nine. Each channel's two hex digits range from 00 (none of that color) to FF (the maximum), which in ordinary decimal is 0 to 255. So #FF0000 is full red with no green or blue (bright red), #000000 is black, and #FFFFFF is white. Because each of the three channels has 256 possible values, a six-digit hex code can specify more than sixteen million distinct colors.

Hex codes are the standard way to specify color on the web because they are compact, unambiguous, and easy to use in HTML and CSS. "Blue" is vague; #1A73E8 is a single, exact color that renders the same everywhere it is read correctly. That precision is why hex codes matter for brand and design work. A brand's color is not a mood — it is a specific value, and writing it as a hex code lets a designer, a developer, and a printer's digital proof all reproduce the same shade. When a style guide lists a brand color as a hex code, it is pinning down exactly which color counts as "the brand's blue," removing the guesswork that plain color names invite.

The most important contrast is between a hex code and a plain color name. A name like "red," "navy," or "teal" is human-friendly but imprecise — different people and different tools will render it differently, and there is no single navy. A hex code removes that ambiguity by naming the exact red, green, and blue values, so #000080 is one specific navy and nothing else. This is why design systems and brand guidelines specify colors as hex codes rather than words: consistency depends on precision, and a name cannot deliver it.

Hex is also one of several equivalent ways to write the same RGB color. The same color can be expressed in an RGB notation that lists the three channel values as decimal numbers (0 to 255), and formats exist that add an alpha channel for transparency, extending the six digits to eight. Hex and decimal RGB describe the identical color in different notations — #FF6600 and its decimal RGB equivalent are the same orange. Hex is favored on the web mainly for its brevity and long-standing convention. The practical point is that a hex code is a specific, portable way to record a color, interchangeable with other RGB notations, and far more reliable than a name for anything that has to reproduce a brand color faithfully.

Using hex codes well is mostly about discipline and documentation. Define your brand and design colors as exact hex codes in a style guide or design system, and use those codes everywhere the color appears in digital work, rather than approximating with names or eyeballing shades. When you hand off to a developer or a partner, give the hex codes, not descriptions, so "the brand blue" cannot drift into a slightly different blue. Keep a small, deliberate palette of documented codes instead of accumulating dozens of near-identical variants, which erodes consistency and makes the brand look sloppy across pages and screens.

The failures are the predictable ones. Specifying colors by name instead of hex code invites inconsistency, because names are not exact. Using slightly different hex codes for what is meant to be the same brand color — a stray #1A73E8 here and #1B74E9 there — creates subtle mismatches that undermine a polished look. Forgetting that a hex code covers screen (RGB) color, not print, is another trap: print uses a different color model, so a hex code is not automatically a faithful print spec. And relying on remembered or copied codes without documenting them lets a palette decay over time. Treat hex codes as the precise, written source of truth for digital color, and consistency follows.

A hex code — a hexadecimal color code in the form #RRGGBB — specifies an exact color by its red, green, and blue values, making it the precise, portable standard for consistent web and brand color.

Etymology: source.

Search interest for this term over the last five years:

View interest-over-time on Google Trends →

Areas of marketing where hex code (hexadecimal color code) is a core concern: