Is This Discoloration Foxing?

I got a bunch of stamps and albums at an auction recently. I thought this one was just filthy, and the stamps inside do look fine, but now I'm wondering if this is foxing. I was planning on just replacing the binder, but if this is foxing, I need to remove the stamps and throw away the binder and the pages.
Most of the spotting is on the cover, and the edges of the pages. A few of the pages in the back have some spotting on the pages themselves, too.

I'm sorry, I can't figure out how to get the images to show up! And I don't know how to delete this post.

ConnieR I struggled with uploading pictures to begin with. The key is to be sure each image is less than 300 kb. There are apps that you can use to check that & reduce the size if needed. Then it's just a matter of selecting & uploading to your message. One thing I always do after uploading is select preview and the message with pictures will be displayed. That way if something is wrong you can go back and fix it before you post it.

If you notice in the lower right corner is a prompt to send a message to staff. Touch that and ask them to delete your message.