Natural selection has repeatedly led to the evolution of two alternative antipredator color strategies-camouflage to avoid detection and aposematism to advertise unprofitability-but we lack understanding of how ecological context favors one strategy over the other. We conducted a globally replicated predation experiment at 21 sites on six continents to test how predator community, prey community, and visual environment influenced the predation risk of 15,018 artificial paper "moth" prey with cryptic or warning coloration. Results indicated that aposematic strategies fare better in environments with low predation intensity, whereas camouflage strategies are advantaged when other camouflaged prey species are rare and when light levels are low. This study demonstrates how multiple mechanisms shape antipredator strategies, helping to explain the evolution and global distribution of camouflaged and aposematic animals.