There are seven primary colors of the solar
spectrum - violet, indigo, blue, green, yellow, orange, and red (or "Vibgyor").
This puzzle concerns the painting of the four sides of a tetrahedron,
or triangular pyramid. Each time no more than four colors from the
solar spectrum can be used to paint a pyramid.
The question is in how many unique ways may the triangular pyramid be
colored, using in every case one, two, three, or four colors of the
solar spectrum? A side can only receive a single color, and no side
can be left uncolored. The crucial point of the challenge is careful
selection of the painting scheme in order to avoid the repetitions of
the pyramids. In other words if a colored pyramid cannot be placed so
that it exactly resembles in its colors and their relative order
another pyramid, then they both are different. Otherwise they are the
same. Remember that one way would be to color all four sides red,
another to color two sides green, and the remaining sides yellow and
blue; and so on.