Color Shifts

[centurytsr]

We are experiencing a color shift between pages when the same color is being used on each of the pages. The customer has provided us PC InDesign CS files. The pages are like a Chamber of Commerce directory with colored bars to divide the different catagories. These colored bars are "embedded" within the text so as text gets changed, these colored bars move with it. These bars are built with and RGB color (wrong to begin with). The problem is the even page has a different color than the odd page. The pages are being exported to PDF using the same PDF export preset. The color on the even page preflights in Acrobat as being RGB color with a converted build of 61c96m15y4k. The odd page has the color already converted to cmyk and shows no RGB when preflighted. This color build is 98c94m17y7k. What could possibly be making one page convert defferently than the other. It is also random throughout the publication.

 

[apepp]

are these bars rgb images or indesign rgb elements?

sounds to me like the colours are slightly different rgb colors used, can you change the rgb colours in the swatches palette?

Andrew

 

[MarcusStringer]

Yes, change the RGB to CMYK before PDFing.

It should be a matter of changing it once if only one object was placed multiple times. Or twice if a left and right one was placed.

Then update your link pallet

Making sure the left and right have the same convertion values.


Marcus

http://www.midlandtypesetters.com.au

 

[centurytsr]

Yes, they are all InDesign elements. Nothing has been imported. The RGB builds are identical, but when PDFd they convert to 2 different color builds. The RGb color that was used is not listed on the swatches palette.

 

[jmgalvin]

If the rgb is not listed on the palette, it was probably imported from another app. This is common when importing things from apps like Word and Excel or databases. Just had that about 2 weeks ago with a table done in Excel - background of cells in rgb and not showing on palette.

You can try selecting "add unnamed colors" on the flyout menu of the swatches window. If that works it should show up with its rgb values as the name. You should be able to then change to the cmyk that you need and save. If you can do it, make sure to click on a few random (old rgb) items throughout the doc to make sure thay come out as the correct cmyk

Using OSX 10.3.9 on a G4

 

[centurytsr]

But what would be causing the same RGB color on an even and odd page to convert to 2 different cmyk values when exported to PDF? InDesign is doing the conversion when making the PDF. When converting the color in the list before PDFing, the color is consistent. The files were submitted PDFs from the customer, however, I am able to reproduce the problem from the customer's submitted native files. Why would InDesign convert the color differently? And, it is not even consistent. One even/odd facing page, the converted colors match, but the next even/odd facing page has different converted colors.

 

[jmgalvin]

I'm guessing because the person who did the original used slightly different values. If you one of those little palettes that come with various apps, it's very easy to pick one chip that's next to another but only has a very slight difference in the value.

You will even get shifts if you bring in an rgb from Photoshop and then make that same rgb in ID. The result can be off and increase when changed to 4 color.

There can be a zillion reasons why things shift, but Indesign is not dopng this on it's own, it's only seeing what's already there and using that.

The falult here is with the person who sent you the Indesign file.



Using OSX 10.3.9 on a G4

 

[RegistrationMark]

different transparencies, or opacities, or overprinting objects, can produce different results.
conversions from RGB to CMYK should have a rendering intent set to Perceptual.
also if your RGBs have different source profiles they will convert differently.
Those are all the possible reasons for color shift I can think of right now, but I bet there are some more.
I'm a little confused though as to why in preflight your right page comes out as already converted CMYK, but the left is still as RGB. If they were built the same they would preflight the same. Perhaps I'm just reading it all wrong though.
Good luck
Mark