Unity game code. How do I draw a regular, one-color, no shading line?

Hi

I've got my game's play screen basically locked in.

Sadly, drawing solid lines, - using a shader only makes an aesthetically pleasing blue blend blue to red mixed line, from GamedObject to GamedObject. 

I'm using this Unity page's style example code.  here

I can't see a page to indicate a solid one-color line. (not a blend) / shader

What should I change?

Thanks