Practically any. Beige is a very neutral and "flexible" color.
White or Grey.
beige goes with brown and blue very well
any fall or calm color if not an idea look at fall colors outside.
Beige
Any colors will go with a white shirt
Every color!!
plain white tee.... or a tan coloured shirt nuetrals perferrably, you could do gray too
Every color!!
Depends on what you are matching it with. What color is your suit/pants? Get that color on your tie and you should be OK. Medium grey (in a glen plaid) or tan could work.
light beige
Gray pants will go well with any color. I would chose something depending on the season and the event you are attending. Bright for summer and spring,
Army Pants and a Army Shirt