There are certain colors that just work well together.  Unless one is trying, it's relatively difficult to go wrong with some combination of navy and gray.  As long as the shirt and tie are tasteful, I think you're on the right path.  Similarly, I've found that mixing a nice hunter or moss green tie with a navy suit just seems to work well, especially when I feel the need to lean in a more conservative direction.  

As I've continued to work on my wardrobe particularly in the areas of fit and quality, I spent some time searching for a new navy suit.  I initially considered a couple of made to measure options but ended up taking so much time to make my decision that I ended picking up this one from Ring Jacket.  Ring Jacket came to my attention via social media and I admired their work from afar.  I have been quite pleased with my decision as the jacket fit well off the peg  and the trousers only needed a bit of a taper to suit my personal preference.