Hello,
1. Your contacts might not be aligned on the grid. Try to enable Object Snap On and Snap to Grip. Then select your contacts and click on Align on Grid.
2. You can use "Connection Definition Points". Place them on the connection you want to modify and change the Color in the Connection Graphic tab. Additionally you can create your own layers with default line color and thickness for various supply types (L, N, +, -, M, PE, SH, etc).