Chrome is a browser - not designed to open kmz files
you have 2 choices (provided that you have Google Earth installed)
#1 tell your kmz file (in attributes or settings) that it and all other kmz files want to be opened with Google Earth
#2 open Google Earth, chose "Open..." in the file menu, select the kmz (or kml, or gpx) file that you want to open.
once the file is open you can change it in any way you want with cmd-I
colors, line thickness, location, icon, label, add web links etc etc |