Answer :

That's a physical change. There are no chemicals reacting with each other, it's the simple presence of concentration of food colouring and oil in water that changes its appearance.
Both are physical. it's not changing the actual substances; by adding food coloring, you still have water. the formula for the compound hasn't changed, and you can separate the food coloring from the water. They aren't bonded together 

As for boiling water, that's just changing the state of the water. if you cool the water down, it'll change back to a liquid.  

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