The Sith Empire was known to have a variety of uniforms and armor for their military personnel with the idea of having them stand out amongst their enemies. This ranged from simple uniforms to full armor suits.
Trooper
Sith Trooper
Sith troopers had armor with reflective styling and black face mask, the armor covered the wearer completely, and even had a one-way visor. They also were protected by sixteen silver plates attached to their uniforms. The majority of Sith troopers wore armor with a silver sheen, some higher ranks wore crimson colored armor.
Officers
Sith officer, male
Sith Officers wore a blue jacket with campaign ribbons on the left breast, as well as rank symbols on either shoulders. They wore light gray pants as well. They also had black boots and black belts on which they carried their blaster and comlinks. A hat symbolized officer status. Gloves were optional.
Sith General
Generals wore a uniform identical to the regular Sith officer's uniform save for more medals, with green and had red cufflinks.
Sith Fleet Commander
Fleet Commander uniforms consisted of a black jacket with gray rank identifying pauldrons at either shoulder. There were campaign ribbons on the left breast, and a red sash coming down from right shoulder. Red and gold command status symbols were worn at their left and right collar. They also had light gray pants and a gray hat.
Sith and Dark Jedi
Sith Warrior
Sith Warriors wore mainly red and black. They had bulky, red, shoulder pads and what appears to be an overcoat. They also wore a red helmet with a small slit, presumably to look out of. They wore black pants and large brown boots. Sith Warriors did not use weapons, fighting instead with their armored hands.
Sith Marauder
Sith Marauders wore black tops and pants, they also wore a black belt and shoes. It appears that under their black top they wore a red top with a slightly higher collar.
Sith Acolyte
Sith Acolytes wore green and orange with black boots and an orange hood. They wore fingerless gloves and left their face, apart from the hood, unguarded.