Hiya Yuki!! XD
I tried to extract Sebastian, but they put a tight chastity belt on him. He's all encrypted from being DLC. Maybe someone will know how to get around that, but for me he's locked up tight
So it seems like we either have to remake him and put that file in override, or replace that bright blue eye tint with another one, and change the color across the board.
I haven't found where the eye tints are -- I think they might just all be numbers, with the RGB to change for the tint. Or maybe those were different tints I found. Someone else would know more than me. Anyway, I came up short on the eye tint front too.
So right now it looks like the only thing to do is get a .erf from nexus (there's 2 sebastian's at the moment) or make one.
I dream of new eye colors to add to the mix! The old style don't work, they just give them black eyes. Which hey -- you could make everyone with his color of eye have black eyes