As Pat has mentioned, some Colombians can be a bit potent as an S/O, but if you want to, you can tame them by blending with a milder bean. I have used them in various ratios with a Peruvian, and with a couple of Indian beans. They go well with Tiger Mountain and Elephant Hills. I suspect that almost any bean that's a bit bland on it's own could be given a lift with a good Colombian. i have had a Colombian that was good in milk coffee on it's own, and another that was great as an espresso, but sadly neither of them are currently available from suppliers who sell to home roasters. Not sure how the Pitalto's would go with an Indo or a PNG but if you roast separately and post blend, you won't waste a whole batch if they don't play well together. Of the two I think I would try the PNG, but that's probably because the Indo's I've tried were also strong flavoured, albeit different from a Colombian.