Coloring problem is a very interesting mathematical problem, and the four-color problem (any map with only four colors can make countries with the same border dye different colors) is one of the most classic coloring problems. The potential of students is unlimited. We should make full use of points, lines, planes, bodies and their relationships to improve students' spatial concept and ability to solve practical problems.

In the mathematics of college entrance examination, the dyeing problem in permutation and combination is generally a difficult problem, mainly because the classification discussion is troublesome; Now there are fewer dyeing questions in the exam, but we can also master the types and solving methods of common dyeing questions, which is helpful to deepen the understanding of permutation and combination.

The formula of cubic coloring problem is (n-2) square ×6. There are eight paintings on three sides. The color of both sides is (n-2)× 12. What is not drawn is the (n-2) cube.

A three-dimensional figure surrounded by six identical squares is called a regular hexahedron, also known as a cube or cube. A regular hexahedron is a straight parallelepiped with square sides and bottom, which is a hexahedron with equal sides. A regular hexahedron is a special cuboid. The dynamic definition of a regular hexahedron is a three-dimensional figure obtained by translating the side length of a square in the direction perpendicular to the plane of the square.