MacOS. 10.15.7 Affinity Publisher 1.10.4
I am preparing a book of black and white photos to be printed in four color B/W. The picture files are RGB placed into my Affinity doc set up in cmyk. Images which I adjust (levels, brightness/contrast etc.) in Affinity Publisher all show a colour shift. Most of the time the shift is very subtle and barely noticeable in Publisher but when I export to PDF the shift becomes very obvious. The greater the adjustment, the greater the colour shift usually towards blue. I have used the same method to publish full colour images with adjustments giving no adverse effect.
Is this a bug or am I doing something wrong?
See the attached screengrab