The side stripes rarely match the Lemans stripes. The Lemans stripes often were Caspian blue. Some were Guardsman. It depends on who painted them.
The side stripes didn't match the GT350 either. You can always tell an original car. None of the blues match.
The point is, they were 'supposed' to match. There are any number of factors that could attribute to the colors not matching exactly, the most relevant being how much paint was applied. Spraying blue metallic over white, with each pass of the gun the color appearance would change from light to dark.
Even observing a car now with original paint/stripes, would be subjective based on how the car was stored and used, was it polished a lot, what part of the country, etc...
My paint guy was very put out painting lemans and side stripes on a 65. Can only imagine how much the guy that did it all day disliked the process.