Hippie Modernism

A book that got suggested to me was Hippie Modernism. I ended up finding it absolutely fascinating and took a few images that I felt was the most exciting out of the book. The use of colours and shapes really get me inspired. The shapes are all just so different and weird and confusing which is quite exciting to look at. I like how they've managed to create some images that look like you might be on a trip or hallucinating which again I find quite fascinating. 

How have they managed to achieve such a weird look without it looking too odd?