Brasília is 8.5 hours behind Colombo
Best overlap: 5:00 PM to 6:00 PM in Colombo is 8:30 AM to 9:30 AM in Brasília.
Colombo and Brasília overlap from 5:00 PM to 6:00 PM (Colombo) to the equivalent 8:30 AM to 9:30 AM in Brasília — that's your meeting window. You've got roughly 1 hour — enough for a focused daily check-in if you hold it at 5:00 PM in Colombo (8:30 AM in Brasília).