Add flour and mix. If dough is too try, add water until dough is slightly tacky.
Turn dough out onto floured surface and knead for 1-2 minutes or until smooth and pliable.
Split dough into equally sized balls, one for each color you will be using.
Color each dough ball.
Roll dough to 1/4" on floured surface. Use a cookie cutter to cut out hearts.
Place hearts on a greased or lined baking sheet and bake at 300° for 15-20 minutes.
Notes
There are 7 traditional conversation heart colors: white, pink, orange, yellow, green, blue, and purple. I used a mini-heart cutter to make these look more like the originals.