I'm about to go out and buy a smart thermostat for my place and had a question about the 'c' wire (common wire). From what I've read online, the blue wire is commonly known to be the c wire for the thermostat. Below is a picture of my current thermostat terminal and I am somewhat confused because my blue wire is set into the 'Y' terminal and the yellow wire is unused. Does anyone know if the blue wire here is really the c wire?
EDIT: I got into the furnace motherboard to look at the terminal and here is what I have found:
(yellow wire is not pictured below but it is clearly not connected to the terminal.)