A helpful introduction to his philosophy around will and representation before reading his major work. Although I feel compelled by his ethos at particular points and his attempts to make Kant's philosophy more concise and readable, I feel like many elements are underexplained. Outside of the ideas regarding representation (what we see/interpret through representation is what truly is), the colour theory is largely superfluous: Schopenhauer comments multiple times that Einstein's ideas are wack and a conspiracy haha. He also clearly loathes Hegel, mentioning several times across all the works what a hack he is ahahaha
The concept around being/identity described as a 'will' is fascinating, however Schopenhauer seems to take this too far to the point that he would seem to indicate all existing things (people, animals, and even matter/forces) are self-creating, self-willing, and self-sustaining. He even describes non-sentient forces of nature (i.e. gravity) as having a 'will' of its own. He claims that "all [philosophers'] systems...[agree] that the what is most important, indeed, what alone is essential in all of existence, that on which everything depends, the actual meaning, the turning point, the point of it all (if I may say so) lies in the morality of human action. But ...[concerning the ways and means] they are all greatly at variance". He states that religions are expressions of "all sorts of images and myths" seeking to interpret this broad idea of 'morals'. Though he includes quotes from several religious texts and claims agreement with aspects of them, Schopenhauer seems to have no concept in his philosophy of an intelligent creator who imbues life and matter with its identity and purpose. I'm sure that Schopenhauer was a basis for Nietzsche, who took the idea of 'will' even further to the 'will to power' resulting in Übermensch