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I have a strange problem with Illustrator. The company I am working with has a stock hex colour - #0074aa (1).

According to online conversion sites, this hex code translates to the CMYK of:

C:  100
M:  31.6
Y:  0
K:  33.4

When I add these CMYK values to Illustrator as a colour swatch, these translate to a slightly darker, deeper blue (2). Alternatively if I add a swatch with the Hex value of #0074aa, the CMYK values are completely different.

Confusingly, if I put the translated CMYK values that Illustrator came up with after entering #0074aa into an online converter, the resulting hex match is completely different - a bright cyan blue (3)!

Does anyone have an idea as to why this is occurring? When I sent a business card design I made to the printer, the colour printed out was the bright cyan; hence why I am trying to figure out the reason for this problem.

I send my files to the printer by PDF. I'm working in CMYK mode in Illustrator CS5. Viewing the CMYK on iPhone also shows the bright cyan colour.

Colour differences

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3 Answers 3

This is not strange at all. It's one of the rudiments of digital color.

The glaring omissions in your data are the color profile the hex value is presented in and the color profile that the CMYK numbers are presented in.

"Translate to CMYK" is meaningless unless you know the color profile you're starting with and the CMYK color profile you are targeting. In fact, using "online conversion sites" when you have the best in the industry built into your software is like buying a car from Fast Eddie's Used Cars and Chinese Laundry when you have a Lexus parked in your driveway.

Numbers are just numbers. They don't represent colors, they map to colors in a specific color profile.

You need to do the following exercise for yourself to really internalize the point. It's quickest and easiest to demonstrate in Photoshop:

  • Open Photoshop and a new blank Photoshop default document.

  • Open Edit > Assign Profile and make it sRGB if it's not already. Close the dialog.

  • Make a patch of #0074aa in one corner.

  • Edit > Convert to Profile and choose Adobe RGB. Be sure that the conversion Intent is set to "Perceptual" or "Relative Colorimetric".

  • Use the eyedropper to find out what the hex value is of the patch you just made.

  • Make a new patch of #0074aa below the first one.

  • Edit > Convert to Profile and choose Coated GRACoL 2006.

  • Use the eyedropper to find out what the hex value is of the patch you just made.

  • Make another new patch of #0074aa.

  • Repeat for Web Coated SWOP v2 a couple more CMYK profiles, each time checking the hex value of the patch you made just before converting.

You now understand why #0074aa is completely useless number unless you know what color profile it represents.

This is a rock-bottom basic of print production that, frankly, you had no excuse not to be aware of if you're being paid for design work. Be glad it was a $50 print job you can compensate easily and not a $50k one that would get you fired or sued or both.

Buy a copy of Claudia McCue's excellent Real World Print Production and spend some quality time with it. It covers all the important things you should know before you venture anywhere near a print job again.

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It's easier to get a best match from CMYK to HEX than the opposite, and make sure your client understand there will never be an exact match but only a close one.

The suggested CMYK equivalent is a bit "rough" and not always precise. It will suggest you an equivalent by comparing the 2 color gamut mathematically but it's never precise. It's better to find a similar match by using your own eyes, printed charts and the CMYK values. The colors will always look different on every screen you'll look at, that's also why you cannot expect to have a perfect match.

But if you need to select a color in CMYK based on a web color, the best is to use a Pantones color chart and select your color there, and use that color converted to CMYK instead.

In this case, your blue looks like a Pantone 286 on coated and 293 on uncoated. Photoshop suggests Pantone 7690.

One way to see your colors well is to use Photoshop and compare them. I used the correspondant CMYK you mentioned and your HEX, and compared them. They are truly different.

CMYK vs HEX

I suggest to ignore the equivalent online and use Photoshop in this way instead:

You will notice:

  • There is a little square next to the 2 swatches above; this represents the gamut the CMYK can print and the closest match. It is suggesting you a similar blue to the one you got online and it doesn't look right.

  • You can also see the option "color libraries"; that's where you'll find the Pantones equivalent to the recipe that is active. Click it.

Pantone VS HEX VS CMYK

If the color on the top swatch matches well the one on the bottom swatch, go back to the previous screen by clicking "picker."

You will notice a new HEX value and a new CMYK value. Ignore the HEX value. You will use that new CMYK value instead; it's the value of the Pantone the closest to your HEX value, converted to CMYK.

Converted Pantone in CMYK

If you want to see if these 2 colors are very close to each others, enter your HEX value #0074aa in the HEX field; the color of the swatch on top and bottom should be closer. You can adjust your CMYK if you need to by modifying the CMYK values.

How to convert HEX web colors to CMYK

This is not a perfect method, it's better to simply use a Pantones color swatch and put it next to your color on your display, as archaic as it may sound! But it's still a good way to get a better result than simply using the rough conversion from HEX to CMYK.

You could also simply use the color CMYK version your Photoshop gives you for the HEX value, but the advantage of using a Pantone is you can actually see the result already printed on a coated/uncoated paper.

If you go meet your printer, you can ask him to have a look at their Process pantones chart; the CMYK values are written on them! Bring your laptop and stick the color chart on the display until you find a good match. If you plan to print in CMYK, you should use the CMYK side of the chart.

Pantones Pocess Color Chart with CMYK color recipes

Also, you should try to NOT use decimal in your color recipe.

Source image Pantone Porcess Chart: printcatalogs.com

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The catch is that 0074aa isn't any specific color. Look at 1000 screens and you're going to see 1000 different colors.

As such, trust your eyes. If the branding team for your client never got around to picking an official print color, grab a pantone CMYK swatch book, hold it up to a few monitors and pick the color that you feel is the best match.

This is much less about math and much more about trusting your designer eye.

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