Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Nobody really has such colorful eyes! The colors were added digitally after the photo was taken. They represent all the different colors of light. Light is a form of energy that travels in waves. Light of different colors has different wavelengths. Answer: wavelengths

Ex Output:
Different colors of light differ in terms of which important attribute?

Ex Input:
Passage: They will all blend together. The dyes will move through the water until an even distribution is achieved. The process of moving from areas of high amounts to areas of low amounts is called diffusion. Answer: diffusion

Ex Output:
The process of moving from areas of high amounts to areas of low amounts is called what?

Ex Input:
Passage: Stars are classified by color, which correlates with temperature. Red stars are the coolest and blue are the hottest. Answer: blue

Ex Output:
Red stars are the coolest; which are the hottest?