Crimson and Black is a written note found in Dishonored 2.
Transcript[]
Cornella,
I have a special job for you and a few others, coven sister. I'm at work on an important painting, my final masterpiece. And I require some rare pigments to see it to completion. Move in secret. Be quick!
Gather what you need. Use the thighbone of a drowned sailor to crush and mix the colors. Gather twenty banded slugs. Seal them together in a jar until only one remains. It will be large and shiny. Yes, fat near to bursting! Crush it with your fingers, and capture the ooze in a vessel. Use this to give the pigments a finer consistency. My love for you only grows.
Your Empress Forever, Delilah
Location[]
The note can be found in the greenhouse next to the bonfire in Dunwall Tower's front yard, during the mission Death to the Empress.