Some Finder Sidebar Icons Missing?

In the Finder windows, the iCloud Drive and Downloads icons are missing from my sidebar. I use CleanMyMac 2 could that have deleted the icons by mistake?

I have rebooted the icons are still gone.

Yosemite 10.10.2 MacBook Pro (Retina, 13-inch, Mid 2014)

How can I get these icons back? Any idea what caused them to go away in the first place?

Update:

Can't I just drag the iCloud Drive icon into the info panel and change the icon like that? If so where can I find the original icon from?

This generally happens when you've used a utility that changes your sidebar icons to colorized versions. iCloud Drive and Downloads do not use the standard icon format. These products are based on a SIMBL plugin called ColorfulSidebar that does not recognize the non-standard format. Even if you've changed the icons back to the non-colorized versions, the routine that changes the icons may still be running. You have to totally disable the software that colorized the icons.