The colour coding is for the wire size, not circuit.
It would be important to use the block spade connector when you have high voltages and allowing the terminals to rotate may allow arcing from the end of the terminal where the wire goes in to an adjacent terminal.
Using a non-ratcheting crimper (
www.radioshack.com/product/index.jsp?productId=17996146) will guarantee inconsistent crimps with a significant percentage failing.
Use a "full-cycling" ratcheting crimper for a solid connection (
www.digikey.com/product-detail/en/0640160037/WM9986-ND/821379 Home Depot sells one for about half the price). We use ones like this at work to build industrial electrical equipment and make a couple of thousand crimps a day on insulated lugs with no problem. It is important to do a pull-test on each and every crimp. We also use air-powered, automated crimpers that feed the terminals off a reel. The ratcheting crimpers produce crimps of comparable quality.