I was thinking at the beginning that you almost wanted to achieve a very dark blue, almost black. Since you just want a dark candy blue, I would suggest getting a dark blue (very close to the color you want overall). Get this in a fine metallic to cut down on that sparkle you said you didn't want. Then add a couple coats of the candy blue. This should do the trick for you.
Before you do this, take a paint stick and dip it in the candy blue color you would be using. Take it out in the bright sunlight while it's still on the paint stick. Look at it at different angles. If you still see the purple tint to it, then you need to go with another candy blue from a different mfrg like HOK Cobalt Blue