However, I have a vision condition where I can't see blue in my actual fovea. And that point is incredibly small. Maybe 3-4 times smaller than what you are seeing here.
I was under the impression that everyone was blue blind in the fovea due to a lack of short wavelength cones in the fovea. This paper seems to confirm this but it is from 1967 and I am have trouble finding other references. https://www.osapublishing.org/josa/abstract.cfm?uri=josa-57-....
Note that this paper describes a lack of blue cones in only the very center of the fovea, corresponding to 7-8 angular minutes (or 0.03-0.04 mm). That's much smaller than the fovea as a whole, which is about 5 degrees or 1.5 mm. It's unclear whether fudged71 just has this normal condition, or actually has blue blindness over a wider region.
However, I have a vision condition where I can't see blue in my actual fovea. And that point is incredibly small. Maybe 3-4 times smaller than what you are seeing here.