Based on the fact that John saw bright colors and had a strange sensation after eating something, he probably consumed cannabis.
Cannabis is a substance that is sometimes known as marijuana. It is often taken as a recreational drug.
It can sometimes lead to hallucinogenic effects such as seeing things that aren't there which is what is happening to John.
In conclusion, he most probably took cannabis.
Find out more on cannabis at https://brainly.com/question/7575959.