It was Blue, I think since Black and the others did not belive him, He decided to put poision in Black's food when no one was looking.
But Salmon would have saw him, right?
So Blue replaced the Poision label with a ketchup Label.
This is a really stupid guess... i guess i'm dead.
Green Was The next target, First the murder tried to shoot Green, But it missed and hit his hat. Then the murder knew Green would Tell Everyone, so He Smashed Green with the bookshelf he was at... or FORCED to be at.
Well... I dont have time for a scene, so let's say.. i think Pen might Win.
He was bland at first, but he got more character devolempent with more people elimanated.