The sun in space is pure white - not orange or yellow. It's only the atmosphere of the earth that makes it appear orange / yellow. In various scenes that take place on the moon, the earth is depicted in the background. The earth is always depicted as appearing far larger than it actually appears in reality.

2001 is primarily a technical film. The reason it is slow, and filled with minutae is because the aim was to realistically envision the future of technology (and the past, in the awe inspiring opening scenes).

Stanley Kubrick was a genius of a film maker and this is one of his very best works. And although it is misunderstood by many, and respectively underrated, it is considered one of the best films of all time and I'll have to agree. Back in 1968, no one had done anything like this before, and no one has since.

2001 was an experiment in film form and content. It exploded the conventional narrative form, restructuring the conventions of the three-act drama. The narrative was linear, but radically, spanning aeons and ending in a timeless realm, all without a conventional movie score.