WXYZ- 4 Intersecting Planes - Rectangular Planes

The next one I tried was four intersecting planes, yet another easy module.
Number of colors = No of planes.

Two fundamental points in any intersecting plane:
1) Each plane intersects every other plane.
2) All planes meet at one center point.

Reference:  http://www.davidpetty.me.uk/origamiemporium/images/ow_wxyz.gif
No of units: 4x3 units. (4 planes, 3 units in each plane)
Paper size used : 5" x 5"  
Difficulty: easy to make units and easy to assemble.
Paper used: normal color printer paper
Time: 2-3 hours

Since the total number of units in each plane is 3, the angle between each plane = 360/3 = 120 degrees.
In case of 3 intersecting planes, total number of units in each plane is 2, angle between each plane = 360/2 = 180 degrees.

Assembling technique:
I started by assembling four units, each of different color/plane, like a valley surrounded by 4 walls. Continue to assemble making sure same colors lie in same plane.