Gamut! Why Sky Blue Prints Purple On Press

bright blue sky with straw umbrella

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I’m sure everyone has seen it before: highly saturated digital photography (RGB image), however the sky blue prints purple on press.┬áThe resulting color is a product of the color gamut your commercial printer prints to or the profile of your inkjet printer.

The rich, blue hue of the sky looks very surreal on screen because of a polarizing filter or just using a wide color gamut such as Adobe RGB. However, when these rich images get converted into a smaller CMYK color gamut, such as SWOP, the rich blue prints purple because those colors are not available in this particular CMYK gamut.

A better solution is to work with a commercial printer that prints to a higher standard CMYK color gamut. prints to the GRACoL color standard, which contains more shades of blue for the rich RGB image to get converted into, especially Adobe RGB.

Below is a comparison of the two CMYK color gamuts – SWOP and GRACoL:

sky blue prints purple
Deeper shades of blue are not available in a smaller CMYK color gamut causing deep blue prints purple.
sky blue prints with GRACoL color gamut
Printing with a larger color gamut, GRACoL, allows for rich blue RGB images to be converted to more accurate deep blues.

Always be aware you have choices when choosing a commercial printer.

Has this happened to you? What did your printer tell you was the problem? Please leave your comments below…


  1. Images should’nt be over corrected if overcorrected the images turn flat and lacks ‘depth of field’ instead selective correction is the best As my experience as a 4 color seperator and color retoucher in the days gone-by I feel the photoshop artist should have true knowledge of RGB versus CMYK RGB is additive Photography and CMYK is subtractive photography, if the photoshopper understands these two terms he can research on the same and experiment with different pictures to create the best print values for offset printing

  2. Purchasing a monitor that displays the Adobe RGB gamut, will give you much more richer color; that would look great while gaming…

  3. hello sir,i’m looking for new monitor basically for gaming .which color profile would you suggest ,srgb or rgb . 2) is rgb profile same as that of ADOBE RGB. please do reply .

  4. Elidio Fernandes

    Why is the sky purple when printed on Press?…well well in color correction it is always necessary to reduce magenta in the sky area in selective color correction mode. I used to do this earlier on Dr Hell Chromograph Scanner, I would increase the Cyan minus some yellow and reduce a bit of magenta. There was a time about 20 years back I loved a light purplish sky (add a little magenta to the sky area minus some yellow and retain the cyan as is) Things have changed over, I no longer like the purplelish sky. there are times when some printers increase magenta to get a purplish tinge in the sky. its a matter of opinion some like a bluer sky and some purple.
    its all fine as long as the sky does not turn deep purple, alittle black may need to be reduced. yellow is a dangerous color as far as deep blue and purple is concerned, sometimes running a little more yellow in printing ca mess up blue and purple areas making them a deep shade nearing black.

    1. Ha..Ha life’s much easier now- a- days for photoshoppers, just move the graph(curves) here and there and they think they have achieved it all. quite a training is necessary, the photoshopper has to love his work, or he is in the wrong proffession, Elidio as you say I agree with you reducing the yellow form the blue skies and all..but how many pohotoshop artist know this? for this it is very important to go to selective colours and accordingly reduce or control colors,
      the old schoolers know this because they have gone through manual 4 color seperations on pan-chromatic films, working in pitch darkness, and then screening the continuous tone images to lith films in liquid chemistry.
      basics are very important to photoshop artist, otherwise doing things for the sake of doing, will ruin the images either by over correction or under correction.
      but things are pretty easy now, and a good photoshop artist or Image Editor (a fancy designation lately) should not only work in curves, but almost all modes in image correction, to achieve fantastic results which are pleasing to the eyes.

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