Step 1:
Each cube is made out of two different color papers. Prefold in half over this line.

Step 6:
Each side of the cube is made of 10 strips.

Step 5:
The cube is made of 60 strips like this one (30 strips of each color).

Step 2:
Fold the edges to the centerline.

Step 4:
Fold in half.

Step 3:
Fold the edges to the centerline.

Step 10:
And weave two more purple strips through the model.

Step 8:
Weave another white strip through the model, see arrows (back - front - back).

Step 9:
Weave two more white strips through the model.

Step 7:
Arrange 4 strips the same as in the picture.
One white strip is already woven through three purple strips.
Weave another white strip through the model, see arrows (front - back - front)

Step 16:
Fold over the purple lines and slide the flaps on the left into the part on the right, see arrows.

Step 15:
Repeat steps 13 and 14 two more times.

Step 12:
The cube is made out of 6 sides like this one.

Step 11:
Use tape or glue to hold the strips together (if necessary).
Mountain-fold over the purple lines.

Step 14:
Slide the part on the right into the part on the left, see arrows.
Glue or tape both parts together, if necessary.

Step 13:
Fold over the purple lines.

Step 17:
Make these folds on the remaining two sides.

Step 18:
Slide the flaps into the top of the cube, see arrows. Slide the final side the same way into the bottom of the cube.