Differences in showing adobe acrobat files using Firefox and adobe acrobat

Hello, In file http://www.bankofgreece.gr/BogEkdoseis/oikodelt201412.pdf there are differences when using Firefox's viewer to show the document and adobe acrobat, especially in colors. Way to reproduce the problem: 1. Open the above page in firefox 2.Save the file 3. Open it with adobe acrobat and see page 12. The line in the right diagram in firefox is grey where as in Adobe acrobat is green. You can also see the problem in http://www.bankofgreece.gr/BogEkdoseis/oikodelt201412.pdf I could select adobe acrobat plugin to show the file but I wonder the cause of the problem. Thank you