I have beige/ivory skin with dark brown eyes (Not your typical combination). My foundation is actually called beige. I don't have a yellow undertone or a pink/blue undertone. However my skin can look ruddy. I've dyed my hair black and it looks garish. Any ideas what colour my hair should be? I can't decide and want to look my best.

By the sounds of your complexion your hair would look really nice blonde.
I've seen many girl that are darker and their hair looks really great blonde.
It makes you stand out more.

With the dark brown eyes combined with your complexion, it sounds to me like your hair would look really pretty a light or medium brown :)

If your skin tone is beige/ivory, opt for a lighter hair color. Black hair can make your complexion look washed out or sallow. Choose colors such as golden blonde, light golden brown or auburn. These colors will look great on you.