I have seen posts like this before- always be better dressed than the guests. To a degree you are there to look like the hired help, not uncle bob's poorly mannered nephew...
As a general rule of thumb, I dress similarly to the bridal party. If they are in tuxes, so am I, light colored suit on the beach- well, I better get out my light colored suit, too.
Also ask the bride and groom during the consult or any subsequent meetings if they prefer you to wear something special. Its a service industry- you are there to serve the bride and groom, not your self. Not sure how I would feel about my photographer showing up in a t-shirt or even a polo with his company name. Feels a little too informal and on the verge of disrespecting your clients to me.
Giving out a business cards when you get the chance is one thing, wearing a billboard is another. :-p
All the best.