Feature idea: Smart highlighting uses a different highlight color for non-case matched entires
Right now you can choose to match case, or not match case, but you could take that further. As you no doubt know, nameSpace is not equivalent to namespace.
Right now, smart highlighting uses a greenish color background for matches, so a reddish color should contrast well against that. That would indicate to you likely instances of mis-capitalization(either in the highlighted text, or the selected text).
One of the most often made and easiest to overlook mistakes would be easy to catch. Of course that might not be for everyone, but that’s what options are for.
Not a bad idea, it might be tough to find a unique-enough default color to be pleasing to all. There’s a red already in use for the Mark feature. Aside from selected text (medium-to-dark grey) and anything else in use that I’ve forgotten, here are the colors that Notepad++ already uses (plugins not considered!):