You can use background-colour with the border-radius property and the browser will round the background-colour to match the radius.
If you are talking about giving the border/border-radius a color then use the border property.
Browser versions are crucial.
CSS rounded-corners are only supported on IE9 and higher.
IE8 and lower will not show them without some workarounds.
Firefox will not work because you have misspelt the vendor prefix -
Should be -
As for IE you are probably not using IE9 or IE10 as older versions do not support rounded corners.