I remember when I was younger, I tried hard to disprove the four color theorem. I remember seeing cases where it didn't work on a donut or a mobius strip. But apparently it works on a sphere.
Now, this confused me, because I was able to create a sphere with 5 different countries, all of which touched each other. Therefore, we would need 5 colors.
Here each of (red, grey, orange, blue, green, brown) seems to touch each other, with orange and blue wrapping vertically and brown and grey wrapping horizontally.