Mix the flour, salt, and sugar. Add the cold butter and break by hand. Mix with hand mixer to get crumbles like mixture.
Whisk the egg yolks well with the water and add into the flour mixture. Knead the dough until it is collected.
Divide the dough into 7 pieces and add the colors you want to each piece.
Shape each piece into a thin roll with your hands. Shape the dough pieces together into a ball so that it becomes a large piece. Roll out the dough with a rolling pin.
Set your oven to 400 F. Line a baking sheet with baking paper. Cut the dough into rectangular pieces. (There are 2 pieces per tart). Lay the rectangles on the prepared a baking sheet.
Pierce each dough with a fork. Put the raspberry jam onto a piece of dough.
Top with a second piece and press the edges with a fork.
Bake in the oven for 25-30 minutes. After removing from the oven, let the pies cool.
Whisk the powdered sugar and lemon juice until it reaches the desired consistency. Spread the glaze on the cooled pies with the help of a spoon. You can decorate them with any sprinkles if you want.