Images provided either as single pics or as part of a gallery are shown in acceptable web-quality. To get them in best available quality you have to download them.
First click on the pic redirects you to the attachement-page, where you see a smaller thumb-like version. When you click on that you get a large image-view where you can zoom in. However colors showing up there are not original high quality but web-standard. To get the best quality available now right-click on that pic and save image to desktop, then open in the pic-viewer of your choice and you’ll notice the difference …