- A fatal stain, say?
- Application to change locks?
- Artificial colour
- Artificial colouring in candy eaten
- Change colour of locks
- Change hue of (fabric)
- Colorant
- Blacken
- Blotting-paper stain
- Blue fluid kept in sprinkler
- Drinks a little printer fluid
- Fluid found in pen, or penknife on reflection
- If a pen is a weapon, the ammo is in painkillers
- Octopus defence used in Helsinki