It would be helpful if you posted the PDF such that we can determine what is actually going on.
Thank you Dov. Sorry, how do I post the PDF? Here is a link to another PDF that is having a similar issue.... When I view this PDF in the browser, the image is washed out. When I save this PDF to my desktop, the thumbnail image on the unopened file is colored correctly, but the full sized image upon opening the file is not. FYI only, my machine is a Macbook Pro.
Looks like you're viewing them in Apple Preview. If so, stop doing that and use only Acrobat or Acrobat Reader.
This also means, stop using browsers.
Bob, thank you. You are correct. I was viewing the PDFs in Apple Preview and not Acrobat and did not realize it. I have been having issues with Acrobat DC not opening properly, even after uninstalling and reinstalling. Usually Acrobat Reader still would work for me, but now it is also unresponsive. I'll trouble shoot that separately and hopefully that will fix this issue. Thanks again.