I think everyone has heard some version of the 'Blue and Green' saying. This has stuck in my head from when I was at school. We had a uniform change part way through high school and had a green tartan skirt with a blue jumper. The tartan had a red stripe through it, so I remember my mother using this saying.
For some reason Craft Cult wasn't picking up my latest Treasury, so here's a screen shot. You can check it out here.