What color shirt/tie to wear with my suit?

I only have one suit.
I used to have a few, but when I moved here to the States from England, I had to leave behind everything that I couldn't cram into my suitcases.
I kept this one because it was the better quality and fit out of the few that I owned.

Anyway, I'm trying to get a better job, and I'm trying to put together an outfit for interviews.
I usually wear sportcoats and slacks with a casual shirt and no tie, so I'm not very well versed when it comes to more formal wear.

I don't have the money for a new suit, so I have to work with the one I have, although it is not ideal.

When I bought it, I thought it was navy blue pinstripe, but now I look at it under natural light, I'm worried it might be black
If it's not black, it's definitely VERY dark navy.

I am caucasian and have quite fair skin, (but not pink) and I have mousey brown hair and blue eyes.
I am 36 years old and will be applying for management type positions, so I want to look sensible and reasonably conservative.
I will be wearing black cap toe Oxfords.

What color shirt/tie combo would be good?
Edited by Jamesbeat - 11/10/12 at 8:13am

Thanks.
I was thinking white or light blue, but I have next to no knowledge of these matters so I thought it would be wise to ask...

As for making sure it's not black, it's pretty much wear this suit or turn up naked for job interviews

Looking carefully under natural light, it does look blue conpared to a black shirt that I have, so I guess it must be extremely dark navy.
I promise that if my prospective employer (whoever they may be) forgives me for my too-dark suit, I will use my new higher income to buy more appropriate garb.

Thanks again

It's ambiguous enough as it is anyway, I had to scrutinize it to determine the color, and even now I'm not 100% sure...

Hopefully other interviewees will look like the cast of 'Resevoir Dogs' and I'll be the best dressed one

I have lots of sportcoats anyway, so unless I absolutely have to wear a suit, I have plenty of clothes to choose from.
Edited by Jamesbeat - 11/10/12 at 1:23pm

Yeah I'll get a light blue too then, helps to have something different in case of a second interview.

Oops!
I just got back from the mall, where I picked up a white shirt.
It's nice, and along with a burgundy tie goes great with my suit (thanks again )

One unexpected problem is that I'm quite heavily tattooed on my torso and my arms, and the tattoos show through the white shirt!
I can wear a T-shirt under it to cover them up, but I have to keep my jacket on, otherwise I look more like 'Russian Mafia' rather than 'Sensible Businessman'.

When I lived in England, I had my own tattoo and alternative clothing business, perhaps the only business where it is unprofessional NOT to have tattoos...