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Scribus => PDF Generation => Topic started by: jens_dkt on December 08, 2022, 01:12:41 PM

Title: RGB color change after export
Post by: jens_dkt on December 08, 2022, 01:12:41 PM
Hi,

I'm trying to export a PDF for Screen/Web but I'm having an issue with the RGB colors getting changed when exporting it. I first noticed it with RGB color 0,159,231 which ends up as 0,159,230 after export.

I've tested it with Scribus 1.5.8 in Windows and in Ubuntu. I've tried different PDF versions and I get the same issue.

To test this further I created two new RGB colors 172,172,172 and 173,173,173.
I apply each color to different objects and after export both objects will end up as RGB color 172,172,172.
It seems as if Scribus will not export RGB colors correctly after a certain threshold.

Can someone help me, am I doing it wrong?

//Jens

Title: Re: RGB color change after export
Post by: RodneyLee on December 08, 2022, 01:47:33 PM
How do you check the colors?
Title: Re: RGB color change after export
Post by: jens_dkt on December 08, 2022, 02:06:12 PM
I've been using photopea.com to open the files to verify colors as I don't have Photoshop.
Do you have a better way of verifying the colors?
Title: Re: RGB color change after export
Post by: AdmFubar on December 08, 2022, 07:59:18 PM
It's most likely just a math issue of converting from hex to decimal and back again.
Title: Re: RGB color change after export
Post by: Nermander on December 08, 2022, 08:05:41 PM
There shouldn't be any such issues from converting between hex and decimal as long as the numbers are integers.

But it looks as some kind of rounding issue.
Title: Re: RGB color change after export
Post by: Aleks100 on December 09, 2022, 03:22:47 PM
Tested in Scribus 1.5.8
- Exported from Scribus as Pdf  - Color Output Intended For Screen/Web
- Opened Pdf in Photoshop, checked numbers with eyedropper,
- Everything OK, got the same decimal numbers