The ship is too heigh and too narrow, it would tip over as it is now.
You could lower the space in between the decks a bit or put the third row of guns on the top deck to make it look better.
So I made Navy Blue and Gold (Yellow but I like the sound of Gold better).
The problem with LDD is that I always forget the Floors to put in so it makes it harder to realise the height for a Minifig in it and the Back Cabins, Wheter they would be high enough.
I was wondering, Do you have a cross section image of your Ship? I would help if when people post MOC ships that if their ships sides are clipped on easily, Wheter they could take a picture of the Decks from a side view. Just my opinion, although it may be to difficult for some people.