Consistency: A couple examples which stem the flow
Consider the flow you can attain when juggling several tasks on several websites and you arrive at Paypal for some reason. Hopefully it's to withdraw to your bank account, but first you have to login (our primary task). The highlighted button is to Sign Up, the Login button is below it in a muted gray. Now I always have to adjust my thoughts to make sure I go for Login. I'm drawn to Sign Up subconciously because it's orange hue is so enticing. My experience here is that I need to be wary when visiting Paypal so I click the right thing. The experience is switched when I do get inside - primary functions such as Submit are now Orange. The lack of consistency with web conventions and within itself need ironing out.
I always like to spot real life example as I go about my day. One that doesn't feel right is good service announcements on the London Underground. You are interrupted to be told "Here is a service update - all lines are running a good service". As most announcements are for delays or disruption most people make an effort to listen. If all is good then it should just be. You are running a service, I shouldn't have to be reminded you managed to get it right - I know; a waiter doesn't say "did you see the way I poured that wine, flawless, not a drip".