Final answer:
The person most likely took a psychedelic or hallucinogenic drug, which can cause visual and auditory hallucinations, a euphoric high, and altered sensory perceptions.
Step-by-step explanation:
The person described in the question most likely took a psychedelic or hallucinogenic drug, which typically alters perception, mood, and a variety of cognitive processes. Characteristically, these substances can lead to visual and auditory hallucinations, such as seeing a tree with 'brilliant purple leaves' and intensely 'listening to the sap running' in it, experiences that are not possible under normal conditions. Furthermore, the sense of a euphoric high and altered senses are consistent with effects produced by this class of drugs.
Psychedelics can deeply affect how individuals perceive the world around them, including changes in color perception and an exaggerated acuteness of the senses. This can result in the person having vivid and intense experiences that are detached from reality, which the described person appears to be experiencing. The individual's current state is indicative of someone under the strong influence of a drug that is known to cause profound changes in sensory perception and mood.