An origami heart with dual color can be made using a one sided sheet of paper by following these simple steps.
How to make a paper origami heart:
Take a square sheet of paper – colored on one side.
Fold the paper in half and unfold to make a vertical crease at the center.
Fold such that the left side meets the center crease, like one side of a cupboard fold.
Now fold the whole model (outward) in half.
Lift the right side and insert in the opening formed by the fold made in step 4.
You now have this model – in two shades.
Make a horizontal fold at the top – the fold here is around 1/2 inch in height.
Make small triangular folds at the two corners.
Open up the folds and flatten at he corners.
Flip. Lift the bottom two corners and fold them towards the center.
Flip and the heart is done.