This is a topic near & dear to my heart, especially for the period 1700-1815. My opinion is that artists tend to make it ‘ sky blue’ which it was not. There is a wonderful book published by the Bavarian Army Museum at Ingolstadt called ‘Napoleon und Bayern’. It is a gold mine on this topic.
The "Sky blue" was a result of wear as the dyes of the uniforms bleached out - especially when worn in the field. That lead to the misconception that this was the original color of the"cornflower blue" Bavarian uniforms.
I think that you are correct. In the book that I referenced above, there is a reproduction Bavarian infantryman’s uniform that is much darker than is often depicted. I wish that someone from the Ingolstadt museum could explain how this uniform Kornblumenblau shade was achieved.