Sugarfoot Jack, you raise an issue I've had arguments about a number of times, with no sensible conclusion. While we are all trapped with trying to use words to describe an infinite gradation of colours, and cannot be sure exactly what we each mean, nor can we be sure that we are not seeing the same.
I've known most disagreements about colours on the borders of blue and green, and I'm nearly sure that most of them are due to what people have learned. Are turquoise, petrol, teal or peacock blues or greens? I've often thought it would be a good experiment to get a full solar spectrum and ask people to mark where they considered the divisions to be.
I say nearly, because I do know that blue-greens have not been seen exactly the same by each of my eyes at some times. Seem the same at the moment, though.
The nearest I get to synaesthesia is directly translating an accent into the sensation of the shape of mouth and throat needed to produce it. I hear and feel simultaneously. Don't know if that counts, though.

Penny