Looking for single crochet color change link

[GotJowls]

I remember previously,  maybe a few years ago, reading a link posted here for easy color change in single crochet graphgans.  I have never really cared to use SC for a graph,  but I'm looking to try.  I've done color changes of course,  but if I remember this link was very popular and there was something about it that I guess was simple and provided a good knowledge foundation for sharp and consistent graph designs. 

 

Thanks in advance if anyone remembers. 

[Granny Square]

This is the only technique I know of working flat, there are other ideas for working in the round/spiral

http://www.mooglyblog.com/switching-colors-in-the-middle-of-a-row/