If there is a question with multiple tags, of which I am ignoring one (should be faded) and watching another (should be made more visible), how will it be displayed for me?
What if I am hiding ignored tags?
A post with a watched tag and an ingored tag gets greyed out by ignore and gets the highlighting for watched. This can be verified with no more than two clicks of the mouse.
If you have ignored a tag and set to hide questions with that tag, then it seems the question does not appear at all, even if it is also tagged with a tag you are watching.