I've just done a clean install of Yosemite, and in practically all of my apps I'm noticing those red underlines whenever I've "misspelled" something (or, more accurately, used an unrecognized name, technical term, piece of code, etc.). I have been disabling it app by app, although even then it doesn't always work - for example, when doing Google searches in Chrome it still shows up, even though I've disabled "check spelling while typing."
I've also gone to System Preferences/Keyboard/Text and unchecked "Correct spelling automatically," but this still doesn't seem to do anything.
Has something gone wrong on my system? And is there any more reliable way to completely disable this unwanted "feature?"