Not sure which water features you refer to. Rivers etc show as blue, but you can change the track colour. If you go into map settings there is a "Track Color" setting which I have set to Magenta which I find much clearer. Note that your need the latest v6.0 firmware (or 5.84 beta firware if you cannot get 6.0 yet) for this to work for existing saved activities.
Thanks for responding. My issue was that water features were not blue but black! It seems that I had "marine" turned on in maps mode. When I turned this setting off, the water features turned blue again. Seem counter intuitive to me.