Crush up a box of graham crackers into crumbs. You can use a food processor or just crush them in a sealed bag.
Mix the crumbs with melted butter and press into the bottom and up the sides of a springform pan, then place in the freezer to firm up.
Mix softened cream cheese, sweetened condensed milk, vanilla extract, and lemon juice until completely smooth and creamy.
Divide the cheesecake filling between 7 bowls, then mix one color into each bowl.
Remove the crust from the freezer and spread the red filling into the bottom. Freeze for 15-30 minutes, until set.
Repeat with remaining colors, freezing each color until set. Your freeze time will shorten for each layer as you go since the cheesecake is getting colder and colder.
Whip the cream sugar and vanilla together on high until thickened. About 2-3 mins until soft peaks form.
When the purple layer on top is set, pipe swirls of whipped cream around the edge and sprinkle with confetti.
Keep cheesecake in the freezer until ready to serve. To get those perfect rainbow layers slice the Rainbow Cheesecake fresh from the freezer, and clean your knife between each slice.