Why does the Templar awareness meter background stay red?
Solution 1:
When the background is red but not flashing, your assassin dens are at risk of being invaded by templars. Personally, I found the den defense mini-game to be quite annoying. As such, I tried to always keep my templar awareness at "anonymous," which is the third state you described. All you need to do is assassinate a few officials and/or bribe a few heralds; I considered that a small price to pay to avoid den defense missions