Blue Dress "B"
Same as "A" but the medals are replaced with their corresponding ribbons.
Blue Dress "C"
Same as "B" but without the coat and a khaki long-sleeved shirt with matching tie.
Blue Dress "D"
Same as "C" but with khaki short-sleeve shirt and no tie.
http://en.wikipedia.org/wiki/Uniforms_of_the_United_States_Marine_Corps