Personally mate, when I was going through the style "re-invention" stage a while ago, I was brutal and threw out or sold everything I wasn't 100% sure I was going to keep wearing. That said, you may be able to work with these.
T-shirts hardly ever look good on their own in my view, but a well fitting blazer or some nice knitwear can do them wonders. My style is quite formal but when I do wear t-shirts, I pair them with chinos and a fine knit cardigan. As for colours, black always works with grey or burgundy. For navy, any shade of brown is going to compliment it.
Generally though, I always find it hard to dress up tees that have any kind of design on them, minus a simple breton stripe.
Sorry I havn't been more specific, but hope that helps!