Hi, I have been using Scribus for 5 years now producing one high quality monthly calendar per year with little issues.
Always the same, I create 11.25 X 8.75 images in Gimp at 300DPI, save them as .png
Insert image frame on a blank 11.25 X 8.75 scribus page, get image, shazam it is there and lovely. Every year the same.
For the 2015 I used Scribus 1.4.1, I exported PDF for printer, it looked great and printed perfect. I don't do my own printing I use PSprint.
For 2016 I used Scribus 1.4.3, same output, printed a little dark so I lightened it up and it looked great but something changed because it printed dark.
This year I just finished it in Scribus 1.4.6, same output, and it looks washed out almost bleached. So I went back and pulled my .sla from the 2016 project, output PDF for printer... it looks washed out too with 1.4.6 compared to the 1.4.3 output. Also noticed the 1.4.6 output was only about 105M and the 1.4.3 output was almost double size bit wise.
So I still have the laptop with 1.4.3 and will just use that unless someone knows of a way to dance around this or to specifically load 1.4.3 in Ubuntu replacing 1.4.6.
Sorry for a long first post but I couldn't find anything specific to what I have noticed.