Adun your beautiful country is spectacular and we can't wait to go back although the temperatures of around 4 to 10 degrees C. took some getting used too. ;-)
I'm not good with such cold temperatures. I live 400km south west from where you stayed, in a valley between the western and central Andes, where it's spring yearlong, always around 24°C (±4°C).
If you visit Colombia again, you should stay longer. There's just way too much to see.
If you need ideas:
There's the "Sierra Nevada de Santa Marta" route, where the video the OP posted was recorded. It's the very northern tip of the country, and has ecosystems from the Caribbean (seabirds, flamingos, etc) and the coastal guajira desert, up to the Sierra mountains (snowy peaks) all within a relatively small area. (Also nearby is Tayrona natural park, with my favorite beaches, see my avatar).
Then there's the coffee region, 200km west from the (central) capital, between the western and central Andes. You could spend a week at your "base of operations" in the city of Pereira, or the neighboring city of Manizales, and from there, go on daily treks to ~6 different destinations/ecosystems in nearby national parks. I was just there for Pereira's local bird fair last March. I think Manizales will host their bird fair in November.
Then 200km South from there, you have another route (the Pacific & cauca valley route). From the city of Cali (where I live) as your base of operations, you can take several daily treks to 5 different destinations on ecosystems ranging from tropical dry forests to cloud forests, mountains, all the way down to the Pacific ocean. The city of Cali itself has over 100 species. The Colombia Bird Fair was held here last February.
There's many other, more remote places, such as the Orinoco plains (the very old Guiana tectonic shield), the Amazon jungle and the higher southern Andes, but for time efficiency in longer stays, ease of access and staying closer to civilization, the ones I mentioned earlier would be my recommendations.
