What is this snake? !enter image description here What kind of snake is this? It was sighted in Singapore (South-Eastern-Asia) and was ca. 40cm (~ 16 inches) long.

Could be a Temple Viper ( _Tropidolaemus wagleri_ ). Hard to tell from the picture, but the head looks spaded like a Temple Viper's and I think they come in the green morph you show