Michael McElhinney, 24, targeted two people in Clydebank with a bucket of house paint, on two separate days.
On September 24, McElhinney spotted a woman he knew leaving a friend's house just before 6.30pm.
He scooped a handful of pink matte emulsion paint from the bucket and threw it in the 46-year-old woman's face, and continued throwing more paint at the 'terrified' woman.
The following day, just after 7pm, McElhinney approached a punter leaving a betting shop who had stopped in the street to examine a receipt.
McElhinney poured paint over the head of the stunned 55-year-old man - who was a total stranger.
A judge at Dumbarton Sheriff Court sent McElhinney back to jail, telling him the risks posed to his victims' eyes and breathing was 'outrageous'.
Sheriff William Gallacher said: "I'm shocked by what I have seen. Horrified. I have never seen a case like this.
"That must mean that everyone would grasp that an attack of this nature is so outrageous, nobody would contemplate doing it. It's violently and vigorously thrown at somebody, causing them to be drenched in paint.