Take idli batter divide into 3 parts add salt in it
To first part add tomato puree to make orange batter
To second part add green chutney made up of coriander leaves green chilli
Rest keep it for white batter
Heat non stick pan/tawa pour little oil
Pour the batter with a spoon on top with orange batter in between white batter and lower portion with green batter
Cook on both sides by drizzling little oil
Enjoy tricolor dosa