Allied vs. Enemy Colors?

In Magic: The Gathering, there are 10 color-pairs. They are then also grouped into the “Allied” colors and the “Enemy” colors.

Allied colors are the neighbor colors. So, White’s allied colors are Green and Blue, but it’s enemy colors are Black and Red. Blue’s allied colors are White and Black, and it’s enemy colors are Red and Green. And so-on around the color wheel.

So, there are 5 “Allied” color-pairs (and the Ravnica guilds that go with them):

1. White-Blue (Azorius)
2. Blue-Black (Dimir)
3. Black-Red (Rakdos)
4. Red-Green (Gruul)
5.  Green-White (Selesnya).

And then there are 5 “Enemy” color-pairs (again, with their respective Ravnica guilds):

1. White-Black (Orzhov)
2. Blue-Red (Izzet)
3. Black-Green (Golgari)
4. Red-White (Boros)
5. Green-Blue (Simic)