It’s definitely got nothing to do with Coco Chanel. Society’s standard of beauty is what it has always been: to look like one is rich and does not have to work. When the majority of work was done outside (agriculture and manual labor) and calories scarce, most poor people were tan and skinny. The rich were pale and plump. Now that the majority of wageslave work has transitioned to be indoors and sedentary, and the cheapest food is the most calorie-laden, poor people are mostly fat and pale. So naturally the standard of beauty is to look like one frolics all day in the sunshine with a personal trainer.
You're right in general, but the spray tan look isn't so much "frolicked outside in the sun" as "burnt to a crisp".