Description: Conversion of PPTX files with a colored background to PDF shows a clearly visible shift in colors as if color space have been set wrong. There are no settings available to prevent this. Tested on macOS (ARM), Linux (x86 and ARM) Steps to Reproduce: 1. Create a PowerPoint Presentation with a Color-gradient background 2. Convert with `libreoffice --headless --convert-to pdf gradient_test.pptx` 3. See the difference in colors Actual Results: Colours are off and segmented in bars. Looks like some colorspace conversion I cannot control Expected Results: Same colors and gradients Reproducible: Always User Profile Reset: No Additional Info: See my Forum post for Example files and pictures :) https://ask.libreoffice.org/t/powerpoint-to-pdf-conversion-changes-colors/105199
Created attachment 193997 [details] Test Powerpoint Document
Created attachment 193998 [details] Refrence Picture Colors Result PDF
Created attachment 193999 [details] Refrence Picture Colors Source PPTX
Created attachment 194096 [details] Compare 2-stop with 3-stop gradient in pptx The interpolation of a two-stop-color gradient is different to a three-stop-color gradient in MS Office even if the third stop is at the same place and has the same color as the start or end stop of the two-stop-color gradient. MS Office seems to use a somehow quadratic interpolation in the two-stops-color gradient case. Open attached document in PowerPoint. It has in the middle a rectangle with two-stop-color gradient and below it a rectangle with three-stop-color gradient. Above is a screenshot of the two rectangles as rendered in PowerPoint. Then open the file in LibreOffice. LibreOffice has only linear color interpolation, same as MS Office uses, if three or more stops are present. So when you want the color interpolation to be the same in LibreOffice as in MS Office, you have to use at least three color stops in MS Office. I have added a screenshot to the file, because MS Office does not export the two-stop-color interpolation the same way to png as it renders it.