Treating an off-white such as #F8F8F6 as acceptable where a platform specifies pure white, when only #FFFFFF passes.
Colour
Hex colour
Also called hex code, hex color or #ffffff. Here is what it means, when it changes what you export, and what people get wrong.
ColourRuns on your deviceUpdated 10 August 2026
The short answer
A hex colour is an RGB value written in base 16, prefixed with a hash. Each pair of digits gives one channel from 00 to FF, which is 0 to 255 in decimal. So #FFFFFF is pure white, #000000 is black, and #FF0000 is full red.
Updated
The short version
Hex colour at a glance
| Quick fact | Detail |
|---|---|
| Base | Hexadecimal, 00 to FF per channel |
| Decimal equivalent | 00 is 0, FF is 255 |
| Pure white | #FFFFFF |
| Forms | 3, 4, 6 and 8 digit variants |
| Alpha | The optional fourth pair, 00 transparent to FF opaque |
| Colour space | sRGB on the web |
Slide the table sideways to see every column.
How do you read a hex code?
Split it into pairs. In #3A7BD5 the first pair is red, the second green, the third blue, each running from 00 to FF. Because hexadecimal counts 0 to 9 then A to F, FF is 255 and 80 is 128.
Three shorthand forms exist alongside the standard six digits:
- Three digits.
#F80expands to#FF8800by doubling each digit. Handy, but it can only express a fraction of the full range. - Eight digits.
#FF0000CCadds a fourth pair for alpha, where00is fully transparent andFFfully opaque. - Four digits. The shorthand version of the eight-digit form.
Why does #FFFFFF matter for product photos?
Because it is exactly what a pure white background requirement means. Amazon's product image requirements state a pure white background of RGB 255,255,255, and Walmart Marketplace asks for the same on main images. That single value, and nothing near it, is what an automated check looks for.
A photographed white backdrop almost never lands there. Studio paper under decent lighting typically samples somewhere in the region of #F7F7F5, which looks white to your eye, reads as a faintly grey rectangle against a white listing page, and fails a pure-white test. If you cannot light the backdrop up to full, replacing it is more reliable, and #FFFFFF is the value to set when you do it with a background replacement tool such as Photomop's.
Which colour space is a hex code in?
sRGB, by convention and by specification on the web. A hex code carries no profile of its own, so #3A7BD5 in a stylesheet is defined as an sRGB colour and will render as a slightly different blue if something interprets it in a wider space.
This matters when you match a brand colour between a website and a printed catalogue. The hex code fixes the screen colour; the ink equivalent has to be derived through a CMYK conversion or a spot colour reference, and some vivid hex colours simply cannot be printed.
What people get wrong about hex colour
Each one is a real failure mode, not a style preference.
Assuming the eight-digit form is understood everywhere, when older tools and some print workflows only accept six digits.
Expecting a hex code to print exactly as it looks on screen, when vivid screen colours often fall outside what ink can reproduce.
Sampling a hex value from a compressed JPEG edge, where compression artefacts shift the colour by several steps.
Questions people ask
Hex colour, answered
The follow-up questions people search for once they have the definition.
What is the hex code for pure white?
#FFFFFF, which is RGB 255,255,255. That is the exact value marketplaces mean when they require a pure white background. Anything lower in any channel, such as #FEFEFE, is technically a very light grey and can fail an automated check.
Can a hex colour be transparent?
Yes, using the eight-digit form where the final pair sets alpha, so #FFFFFF00 is fully transparent white. Support is normal in modern CSS and design tools, but many older applications and print workflows only accept the six-digit opaque form.
Why does #FF0000 look different on two screens?
Because the code names an sRGB red, and each display reproduces that instruction with its own primaries, brightness and calibration. On a wide-gamut screen in software that ignores colour management, it renders as a more saturated red than intended.
How do I get the hex code of a colour in my photo?
Use the eyedropper in any editor and switch the readout to hexadecimal. Sample several points rather than one, especially on a backdrop, because lighting falls off towards the corners and compression shifts values near edges.
Same cluster
More from the glossary
Neighbouring entries, so every term in the set is one hop from every other.
ICC profile
An ICC profile is a standardised file that describes the colour behaviour of a device or a colour space.
Hero image
A hero image is the large lead visual at the top of a page, usually the first thing a visitor sees.
ICO
ICO is the Windows icon format, a small container that holds several sizes and colour depths of the same image inside one file.
From the studio
Tools that do this
Each one runs on your own device, so the photo stays where it is.
Sources
Where the facts on this page come from. Every link opens the specification, standard or documentation the claim was read at.
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