What a really terrific house! A classic 70's design. I wouldn't change anything about the house itself, just some new landscaping. Houses of that era and like this were typically aggressive (all hard pronounced angles) and fortress like (large windowless surfaces). Don't mess it up trying to make it something it isn't by adding cute colors or the like. Let it be what it wants to be.

Only thing I'd do is use the landscaping to define where the entry is and add texture. Look at houses like at Sea Ranch to get inspiration.