Too much Green in picture

I got my parents a Sony Bravia LCD (46V5100).  We hooked it up and a lot of the blues are showing as green.  We tried to adjust color settings and changed the HDMI cable, but it didn't really help.  Their previous big screen projection TV did the same thing.  They have AT&T U-Verse.  Could it be the coax cable from the wall to the TV.  Any ideas????  Thanks!