I wear black armour, my flightsuit is ESB Fett grey. White or light grey would work too.
A Black flightsuit would go with almost any colour armour, red, green, white, light grey, silver. I'd steer clear of black on black though, as you'd never see it and it's too close to Vader.
My weapon IS a Emperors Royal Guard weapon from the Crimson Empire series, it's a Force Glaive (a vibro-weapon like the Force Pike)