Our organisation is using a brand guidelines document (produced externally) where the hex values and the RGB values of corresponding colors do not match. Both RGB values and hex values use the same color space (as opposed to pantone or CMYK values which have to be approximated in conversions), so I supposed they would match in our document.

For example (recreated for Stack purposes):

enter image description here

These above RGB values written on the color squares (and background color) do not correspond to their hex values.

I often end up with mismatched colors because of shared swatch libraries which are sometimes hex and sometimes RGB, for example when bringing an Illustrator document (whose colors I took from our brand library swatch) into After Effects (where I used the hex code to create a composition's background color).

enter image description here

What could possibly explain or justify creating a brand guidelines document where the RGB and hex do not match? Is it a common practice? Am I missing something here?


3 Answers 3


I've seen brand guidelines with wildly inaccurate HEX/RGB matches.

To me.... when I see this, it seems like someone merely sampled the color in Photoshop and used whatever number shows up without any concern or thought of double-checking things. Often I figure they sampled a CMYK document and pulled the HEX from that. This causes more discrepancy for light, bright colors such as bright greens and yellows. (I've seen yellow actually turn green, rather than staying yellow, using the provided HEX value.)

Truth is that HEX should be what Billy indicated, #00e06c. #00e06c is correct.

No clue why the guidelines you are looking at are mismatched this way. Sometimes you have to overlook clear errors like this and stick with the color that seems more plausible or closer to the CMYK value if it's provided.


Hex codes for RGB colours are simply the RGB decimal numbers expressed in hexadecimal notation (base 16). The hexadecimal number for the green in the example shown is incorrect. The others are wrong too.

The green should be #00E06C




Edit: As to why they are wrong, perhaps it's just an error. The colours are not the same RGB colours.

  • I think you are missing the point. I know they are incorrect, that is why I wrote "the RGB above does not match the HEX above". I am wondering why a famous branding agency would want to do that. Jun 1, 2018 at 23:30
  • @MacroMachine I have no idea. I can't read minds! Ask them. Perhaps it's simply a mistake? Who knows?
    – Billy Kerr
    Jun 1, 2018 at 23:31
  • @MicroMachine If you look at the colours in Photoshop, are the hex ones perhaps ‘web-safe’ versions of the others? Presumably the hex values are meant to be used online, so browser rendering may have been considered important. Jun 2, 2018 at 9:11

Okay, RGB values do not mean anything in themselves. They must be paired with the knowledge of what colorspace they represent. A RGB value in sRGB is very dofferent from one in ProPhoto RGB or Adobe RGB.

Now this is very rarely said in even well made branding guides.Simply because many designers have problems with understanding this. While its not rocket science, it is atleast close to as convoluted.

Now, there may be a mention somewhere in the guide about this read carefully. It would be appropriate to assume hex values are sRGB, because that is a typical browser assumption.

But then its as likely that this is a mistake. But it is just as likely that your guide was made by the summer intern.

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