Visa Entry Requirements for Colombians I think what you might have "heard" is that Colombian citizens do not need a VISA to enter Panama, rather than they do not need a PASSPORT.
The general and universal rule is that Colombian citizens, as well as citizens of any country, should secure and present an authorized passport from their country to travel abroad. To my knowledge, Colombian citizens do not as yet need a visa to enter Panama, but do need a tourist card (which is not good for work), and currently need to post a bond of I think approximately $500 USD.
Check with any travel agent in Colombia for the latest in the ever-changing and ever-tightening Panama entry requirements for Colombians. See also this Search Engine from Project Visa:
http://projectvisa.comPerhaps in the distant past, even a simple passport of a Colombian citizen was not even asked for by Panama immigration at port of entry, but that is long gone, as foreign entry requirements for Colombians have tightened throughout the region.
Panama now hosts a rather large Colombian population, many who have overstayed their tourist stays and some who are working in the country in violation of the immigration tourist status and enjoy getting paid in U.S. dollars, rather then Colombian pesos.
Incidentally, this includes reportedly a fair number of prostitutes and escorts from Colombia engaged in illicit activity in Panama. Panama immigration periodically conducts raids of barrios and red light districts known to host Colombians. Lists of persons "busted" in such raids are then shared with other brother visa officials, such as those at the U.S. Consulate in Bogota.
I know because I handled a K-1 Fiancee Visa for a gringo who met a "lady" from Medellin who, unbeknowst to him or me, had a "checkered" travel history in Panama (she hid this from him and me despite being asked about her travel history extensively by both of us repeatedly.) She was apprehended during such a raid in Panama at a dancer's night house, and put on the "busted" list which then found its way into Bogota's U.S. Consular database. Of course, she was denied the Fiancee Visa on grounds that she was a person of known ill-repute (i.e. prostitution). Under the regulations, "good moral character" is a visa requirement.
Needless to say, the gringo guy, who accompanied her to the visa interview and was informed of the reasons for her visa denial at the visa window by the officer (with her reluctant consent), was flabbergasted and walked out on her in a huff and flew directly back to the U.S. straight from the Embassy.
Moral of the story: Trust but verify. Check for any travel stamps to other countries in your lady's passport and ask a few questions.