Possible Clues:

• Dye-yielding shrub
• Sounds as if one might die with a nothing at all
• Source of indigo dye
• Actor Kapoor
• Actor Kapoor of 'Slumdog Millionaire'
• Actor Kapoor of "Slumdog Millionaire"
• Shrub yielding indigo
• West Indian shrub, source of indigo
• A love for deep blue
• That's a nothing to die for, by the sound of it