Aren't we drawn to colours, vibrancy and symmetry because it's generally advantageous for picking out healthy mates and healthy food? We respond with pleasure to some stimuli which drives us to seek it out more. This responsiveness to certain configurations of stimuli which could be broadly categorised as "beautiful" is co-opted by art and other things irrelevant to food/sex. The response mechanism (excitement, pleasure, drive) is there regardless of what it's being used for by the individual human. People who are particularly sensitive to beauty tend to be sensitive across the spectrum, and have stronger distaste for ugliness as well, further underscoring the point that the key issue is our responsiveness and not any external object's nutritious/sexual value to us.
We like pretty things (symmetry, colour, grace) because they tend to be genetically fitter - goes beyond sex to include food.
Other things which possess these qualities (like a sunset) will induce the same response in us.
People can have higher or lower sensitivity to the same stimuli.
Rough morning thoughts - hope they make sense.