Color changing under graphic inclusion with graphicx

[Ulrike Fischer]

Am Sat, 9 Jan 2021 12:08:34 -0800 schrieb Paulo Ney de Souza:

> I have (a couple) of PNG images with a background color of, for example,
> RGB(80,64,83), that when placed on a page of the same background color with
> {graphicx} -- they show a distinct tonality against the background -- which
> is of the same color.

> PS. For experimentation here are the same images, before and after opening
> with GIMP.

I can't reproduce your problem with the files you provided. 

How do you compile? Which TeX-System do you have? And which viewer
do you use to view the pdf? Can you provide the pdf you get?

-- 
Ulrike Fischer 
http://www.troubleshooting-tex.de/