Image quality issue in slideshow

Hello all,

I face a image color quality loss when images are displayed in the slideshow.
Images are correctly uploaded in the gallery, image preview show them with appropriate color quality (images are Adobe RGB 1998).
The problem only occurs when are are displayed in the slideshow. You can see it at : https://ericpiochephotographe.com/blog/2012/11/22/test-simple-galleria/

https://www.ads-software.com/extend/plugins/oqey-gallery/