On the site below, Travel document as Passport type is being offered.
So check if on the application if there is also a Passport type field. [answered: there is none]
Use the number of the Travel document for the Passport Number and select your nationality as stated in the Travel document.
Since you must submit the Travel document with the visa application, they will see what type of document it is.
Do I need a Visa? | Cancillería
- Nationality: Gambia
- Passport type: Travel document
- Trip purpose: Tourist
returns
VISITOR VISA - TYPE V: for the foreigner wishing to visit Colombia once or several times or to stay temporarily in the country without this being permanent.