The obvious answer would by dye -> lie, but this is only true phonetically, not when written down.
agent
It is capitalized at the beginning of the sentence or when it forms part of the proper noun or when it precedes a person's name or when it is used as a direct address. Examples: Agent Ford Have you seen the report, Agent?
A Fiat car has been bought. You can add the agent (him) if you want. -- A Fiat car has been bought by him.
a double agent a double agent
A security agent is someone or something that has been employed to protect the assets of a business or company. They can be found everywhere, from small corner shops to large international airports. They're also commonly known to wear black clothing and will generally have some form of security ID on them.
dye
This is the diffusion of the coloring agent molecules in water.
ink is coloring fucation is coloring agent
turquoise or teal
Caramel coloring or E150 is the only coloring agent that is used in soft drinks and in cosmetics (Shampoo, Creams and lotions).
Agent.
Crayons are usually made of wax with a coloring agent while colored pencils are made with wood around a type of clay with a coloring agent.
Ethanol or isopropanol and a coloring agent.
cancer causing stuff!
Ethanol or isopropanol and a coloring agent.
A letter you write to your insurance agent/company when you want them to give you money for something you insured with them, explaing why.
If you are referring to colas, Coke, Pepsi, etc., the dark color mainly comes from caramel coloring. There are other ingredients, which in combination add to the color, but the primary coloring agent is the caramel coloring.