On sea duty in the mid-'50s we wore "modified blues", which were trousers with tropical worsted shirt and white barracks cap. All shirts, tropicals and khaki in those days were long-sleeved. I do not recall any particular designation for this uniform, just modified blues. We wore them for some duty situations, and even wore them on liberty in the Virgin Islands in the summer of 1956 (no, we did not attract any).
Spike Berner
1518119
Sergeant of Marines