How do you interpret this???

Question

If Paul substituted yellow paint for green paint in his painting, then which of the two colors did Paul use? Yellow or green?

Please explain in simple terms. Using the word "substitute" can be confusing and I'd like to get it straight. Thanks!!!

Answer 1

He needed green, but only had yellow. So, INSTEAD of green, he used yellow.

So, all the plants in his picture looked like they needed
water. :-)

Hope that helps.

Answer 2

he used yellow