Why are some icons on my Samsung S6 edge gray now after a security/software update?

[AC Question]

I basically went to Settings a couple of days back and did a security update from samsung. I thought it was Android 6.0 but after the update I was still on 5.1.1 so this wa a security update. Anyways my settings icon along with the messages, camera, calculator, clock, gallery, myfiles, music icons have now grayed out. They all look weird. First I thought this means my phone is transitioning to a new Android version. But doesnt seem so. Can anyone help?