Is easier to draw this cube, rather than to describe in words how to draw it ! We used a squared paper to draw (freehand!) the lines that create the cube, counting six segments to the outer cube and three for the inner cube. While drawing you have to follow the instructions carefully, only in that way it will be possible for everyone to realize this op cube!
Is it a small cube in a room or a large cube that lacks one corner?
When we finished the drawing in pencil, we chose two colours in three different shades: dark-medium-light (eg: 3 felt tip pens green dark-medium-light and 3 felt tip pens red dark-medium-light).
Following the three directions of space we colored the chessboards with the colours chosen (the two darkest colours for the first side, the two medium colours for the second side and the two lightest colours for the third side).