Soak saffron with rose water overnight for better taste, color, and flavor.
Grate kaju katli so that there should be no lumps.
Put milk in a pan and bring it to boil.
Now add condensed milk, cardamom powder, grated kaju katli and cook for 2-3 minutes or till it becomes slightly thick.
Once cooked, switch off the flame and add saffron (infused with rose water), mix it well.
Now add chopped nuts which are optional and mix it well.
Let the kulfi mixture cool down for some time.
Once cool, divide the kulfi mixture into three equal parts. I have used green, orange and pink color.
Add colors and mix it well.
Now take kulfi mould , pour each colourful mixture inside the moulds separately and freeze for 5-6 hours or overnight.
To make tricolor kulfi:
Take yellow kulfi mixture and pour inside the mould. Fill 1/3 part of the mould and freeze it for an hour or until set.
After an hour when the yellow layer is set to add the second color of kulfi mixture which is pink,
Fill 1/3 parts of the kulfi moulds and again freeze it until set.
Lastly, add the remaining blue color kulfi mixture and again place the mould in freezer for overnight for 5-6 hours till its set.
Once your kulfi is set, take out from the freezer and rub between your palms so that sides will get loose by the heat of your palm and kulfi will come out easily or you can put the mould in warm water for few seconds and then unmould.