That's funny - I also have aphantasia and described it in much the same as the parent. But your comment threw me, I think of them as plain.

Looked it up, and turns out the ones in Oregon are. https://www.bing.com/images/search?q=oregon+lighthouses&form...

That is not something I have encountered (I don't think), or if I did, I didn't absorb that detail. The words don't exist in my brain.

It probably depends on which ones they have encountered in real life. From a Google image search, it seems that less than half are.