The sinister meeting room with sinister decoration and sinister long black table and sinister chairs set up for sinister meetings of sinister commanders and their sinister sub-commanders is an essential piece of stock architecture. Despite the heroes in an adventure not being privy to most of the meetings in such a room, the very existence of this room should be enough to send chills down their spines. If the PCs are exploring an evil lair, have them stumble across this room.

Describe it in terms so sinister that they can feel the dripping blood of all the people's deaths that have been ordered from within this room.

This is probably also the location of the evil villain's printer that always mangles the paper at the worst possible moment.

It should be black.

Transcript

Tàrkin: Ze Senate is very annoyed with—
PA System: Attention all personnel! It looks like some rogue clones have started shooting officers.
Tàrkin: As Ah was saying, ze Senate—
PA System: Correction to the previous announcement. It was senior officers dressed as clones. All junior officers, please stop shooting clones.
Tàrkin: Ahem. Ze—
PA System: Clones, please stop shooting junior officers.
[SFX]: klik
Darth Vader: {into PA} Clones will stop shooting junior officers, senior officers, and other clones. Now.
PA System: Sorry. Apparently this was all started by intruders dressed as clones. Clones, please protect our visiting tourists from the intruders.
{beat}
PA System: Look, this is not one of those phantom incidents. There appear to be actual dangerous intruders aboard the Peace Moon.
{beat}
PA System: One of them may be a radioactive Wookiee-gram.