Compilers don’t care about how a program looks, or feels. From that respect, they can be quite insensitive. What they do care about is whether or not the programmer has provided instructions it can interpret. If the programmer has provided the compiler with sloppy looking code, it doesn’t care, as long as the logic is correct. The compiler cares about the raw syntax of the program, and whether or not it meshes with the rules embedded in its logic. Humans do care about what a program looks like in its coded state. Without our own set of rules, humans would likely create programs that are unreadable by other humans, and of course some do. But can programs really be beautiful?
It really depends on what you consider beauty to be. Does beauty mean aesthetically pleasing? Many things are beautiful based on this definition, and in some ways this is also true of code. Well styled code looks nice, is easy to read, and therefore easier to comprehend. However beauty is a subtle concept, and truly in the “eye of the beholder”. A programmer from the 1950s would consider Fortran programs to be beautiful in comparison to assembler, or machine-language programs. A Cobol programmer might consider fixed formatting to provide a nice clean aesthetic to a program, and free-formatting, however well done, just don’t hold.
Beauty has nothing to do with the use of clever algorithms, or using covert language features. Beauty in part has to do with the style used to layout the physical program, but it is more than that. A program should be expressive, i.e. the code should be easy to understand, or intuitively readable for both the compiler, and the human. It should also be concise, i.e. short (and that doesn’t mean using fancy tricks, because those programs often verge on being unreadable). Code written in languages like C often is the opposite of both of these characteristics. Does colour make a program more beautiful? Maybe, to a human.
For anyone not convinced, I suggest finding and reading a copy of Kernighan and Plauger’s, “The Elements of Programming Style“.