Cmyk to rgb

[Slettli]

I have made a file in cmyk, but printing will have a rgb 1998, 8bit. When I change the document setup to this the values of my color changes. Then I manually go and enter my codes again, and the colors get verry wrong. Is this a bug or do I do something wrong?

[MattP]

Hi Slettli,

 

I'm a little bit confused of what you meant when you said "but printing will have a rgb 1998, 8bit"? The first thing I would definitely advise is to use the latest beta version as it has a lot of changes relating to RGB/CMYK colours and their correct proofing.

 

If you could give us a little more explanation of what exactly you're doing and/or the .afdesign file (or part of it) then I'm sure we can offer some specific support and get you to the right answer :)

 

Thanks,

Matt

[Slettli]

I use the last beta version. I made a document in cmyk/8, but the place my costumer will print it needs the file to be rgb/8 (adobe 1998 to be specific). When I go into document setup and choose this, the colors change. When I go to check the rgb values its all wrong now. Then I change it to the right value and the color get even more diffrent.

[MattP]

Could you possibly provide me with some information about the colour you're using?

 

i.e. RGB8 document set to Adobe RGB (1998). Input colour = RGB(255,0,0), Observed Colour = (x,x,x), Expected colour = (y,y,y)

 

so that I can test it?

[Slettli]

Could you possibly provide me with some information about the colour you're using?

 

i.e. RGB8 document set to Adobe RGB (1998). Input colour = RGB(255,0,0), Observed Colour = (x,x,x), Expected colour = (y,y,y)

 

so that I can test it?

 

I try to attatch a file with my colors. I design with pantone tpx, but my customer changed printing to digital and now the printer want it in RGB (adobe 1998)

green.afdesign

[MattP]

Hi Slettli,

 

Thanks for that. Basically, your document's RGB profile is currently set to sRGB - this is the application default. You have a CMYK document and when you are going to the document setup dialog and choosing to change it to be RGB8, you are also choosing to change it to Adobe RGB (1998) at the same time and this is where the problem arises... It is doing a single command to convert your colours for the closest representation through the colour spaces you have chosen, so this is why your colour values are being changed to different RGB values.

 

Instead, do this process: Open your document, go to Document Setup. Now choose RGB8 format and press OK. Your document is now in RGB with its default sRGB profile. Click one of your colours and you can verify that it is still showing the correct values in the RGB readout. Now go back into Document Setup and choose the Adobe RGB (1998) profile and choose the button to Assign the profile (i.e. without converting the colours to be perceptually similar) and press OK. Now your document will have assigned the profile and left your colour values alone. Check this by selecting one of your colours and the value will be as you'd expect.

 

In future, you can avoid this by making your document with the correct RGB colour profile. If you know in advance that you will often use the Adobe RGB profile, why not choose this as your default in the Preferences option - this will hopefully save a few headaches over time :)

 

We will hopefully be able to allow a per-format assignment of colour format in the future which will avoid you having to do this 2 step procedure.

 

Hope that helps,

Matt

[Slettli]

I do it just as you say but it looks terrible :-( converting to rgb give ok results, but to assignt to another rgb profile give terrible result.

[Slettli]

but when I coose convert to adobe 1998 rgb the colors look the same but the rgb codes change.

[MattP]

Unfortunately, the colour RGB(50,177,65) specified in Adobe RGB (1998) looks the way it looks... I have created a PhotoShop document in the Adobe RGB (1998) colorspace, used the same RGB values and taken a screenshot - try picking the colours and you'll see that they are identical. I don't believe Affinity Designer is doing anything wrong at all when you do the assign process I described.

 

 

(Affinity Designer on the left with your document changed to RGB8, then assigned to Adobe RGB (1998). PhotoShop with RGB8 document and Adobe RGB (1998) profile on right)

 

By choosing to convert, you are telling the program to convert the colours to try to maintain their visual appearance as much as the mapping between source and destination profiles will allow - but that means the RGB values will change. Be sure of what you are trying to achieve... Do you know the profile the Pantone RGB approximate values was specified in? If so, then assign your document to be that profile and they will look the same. If you want the colours to look as close as possible but use a different profile then you need to convert to the other space but you have to accept that those RGB values have to be different to the ones you typed in, because the ones you typed in look different with different profiles.

[Slettli]

I know that the printer is using adobe 1998 to print, and I want the color to match my pnatone colors. should I use the rgb values that pantone gives or the ones looking the same in adobe rgb?

[MattP]

I'm guessing the Pantone colours you've got are specified with an approximate RGB value in sRGB profile? If so, I think I'm right in saying that you will get the closest matching colour from your print shop if you specify the colour in your RGB document with the sRGB profile set, then choose to Convert to the destination profile. As I said earlier, this tries to maintain the visual appearance of the colours by choosing the destination profile's closest visual matching to the input. Your RGB values will change because they have to in order to make this happen.

 

You should now be seeing the colours that will come back from your print shop (as close as possible). It's important to note that these are very unlikely to exactly match the original Pantone colour as it was a specific spot colour - an ink on its own - but it should be the closest match possible, given that your printer is using that specific profile for their output.

 

If in any doubt, it is always best to get a proof done, or just simply talk to your print shop and tell them that you are providing them with a document in RGB colorspace using the Adobe RGB (1998) profile and ask if you can expect the colours they print to be representative of what you are seeing on the screen (given that as I have shown you above, our displayed colours are an exact match of those shown in PhotoShop with the same setup).

 

Hope that helps,

Matt

[Slettli]

Thanks for the help. And yes the rgb from pantone are in sRGB

[ronniemcbride]

I also like to add that it also important to calibrate your screen when doing print work. Using tools like a Spider or a Color Munki. Also if you are doing any photography work that will be color matched or color corrected you might want to make sure you use one of these: x-rite MSccPP ColorChecker

 

What you see in Display does not always match what you see printed when your monitor not calibrated for your environment.