Possible Clues:

• Botanical indigo source
• Dark blue dye
• As dye plant, use some vanilla
• Kapoor of “Slumdog Millionaire”
• Dye made from vanilla extract
• A big river, mostly deep blue
• Area on African flower not quite indigo
• Kapoor who played the game show emcee in 'Slumdog Millionaire'
• Kapoor of 'Slumdog Millionaire'
• Name hidden in "Can I leave?"