[sureste]

Off-topic, but the number of times people misspell Colombia as Columbia is very high and I'm (more) disappointed in FB for letting it pass.

[copperx]

It grinds my gears too. Mnemonic for anyone that struggles with it:

ColOmbia is the cOuntry.

ColUmbia is the shUttle (or University).

[twic]

Or:

Columbia is named after Christopher Columbus

Colombia is named after Cristoforo Colombo

If you can remember which countries traditionally mostly speak English, and which mostly spoke a Romance language, you have a shot at getting it right.