Jill's mind was not actually a rainbow.That is the metaphor.
aristotle
Chris's mind is a fast-moving river.
having a light go on in your mind
no. It is a simile
Yes, it is a simile. Keep in mind that a simile is a metaphor, but not all metaphors are similes. A simile is a metaphor that uses the words like or as for the comparison.
Some move matter with their mind.
Ideas are created in your mind. Ideas relate to thoughts and plans.
Yes, this is a metaphor comparing a child's mind to a shallow brook that ripples and dances over a stony course as it receives education. The metaphor suggests that education helps shape and enrich a child's mind, just as the brook's course is shaped by the stones it flows over.
I'm not sure if this is what you are looking for, but a sharp mind is merely an adjective because it can't be a metaphor or simile, neither is it a hyperbole or oxymoron. Sharp is an adjective describing the noun, mind.
It is a metaphor because it's comparing bear and death without using "like" or "as".
You're out of your mind means your ideas are crazy.
the colors of the rainbow his mind is limited and so can yours