Can I buy alcohol at Colombo Airport duty-free?

You can legally pick up alcohol at the Colombo Airport duty-free stores in both the arrival hall and the departure hall, yes, even on the same trip. The usual duty-free allowance for arriving passengers is 2.5 litres of spirits and 2 litres of wine.

Be careful here; buying alcohol is strictly for personal consumption only. If you are purchasing alcohol in the departure lounge, double-check the exact customs ceiling at your next destination, because rules for liquid transit across borders might apply.