Color differences jpeg and png

[Redraw]

@rich2005

The colour profiled monitor isn't an issue here,

I did find some things after trying the other suggestions also with the viewing apps and there is some differences,

Gimp, inkscape, okular and smplayer and xnviewmp these showed the images as good quality

Gwenview, Krita and Geeqie these show the images as washed out colours.

( yes I know some apps are NOT dedicated jpg or png image viewing apps as such )
that's not important it's how different the images show in the different apps and I wonder .. why ?
if it's not the monitor
what is the common or difference between the good viewing apps and the not so good viewing apps ?

@plumbergp

I don't know how these issues are in a Windows machine and the apps there, Honeyview would be only only I know of, what viewers do you use, thanks.

Thanks to all for the many ideas and things to try.