I like the idea of having the Sith eyes toggleable. So normal eyes in one shot on the throne, and Sith eyes replacing the milky eyes in the following shot.
Later with the clone, normal while speaking, Sithy while hissing.
It reminds me of ROTS where Anakin’s eyes are Sithy while he’s really deep into the dark side, but otherwise appear normally. Only Palpatine and Maul had Sith eyes that were permanent.