Suddenly, I have BLUE BOX pagination, not default green

Hi,

I am curious how I suddenly have blue box pagination at the bottom of my blog feed. These pagination buttons allow users to go page-by-page to read older posts. I think the default Twenty Fourteen theme uses black/green pagination buttons, but suddenly I found my site using blue/grey boxes for pagination. What happened? How can I put this back to the default?

https://www.youngprodigy.com (scroll down to see the blue pagination)

https://www.satdecoded.com (scroll down to see the default black/green pagination)

Thanks!