My question though, since the SPDT has 6 terminals, which one of those would I be using?
Like Vigo said, you probably have a DPDT switch.
The center-right tab should be the common. (green dot)
The upper-right and lower-right tabs should be the red and blue dot contacts.
You can check for continuity (electrical connection) using a multimeter set to continuity. (or ohms)
-- With the switch set to one position, one lead touching the center-right tab, and the other lead on the upper-right tab, you should get a beep. (or <2 ohms)
-- With the switch in the other position and the leads touching the center-right and lower-right tabs, you should get a beep. (or <2 ohms)
If it doesn't work as expected, try the same multimeter tests using the contacts on the left.
Scott