This is the game of Silver Box.  It's based on Black Box, but with some additional rules.

The basic premise is the same.  Consider the coloured beams to be laser beams inside an opaque (black) box.  Hidden inside the box are atoms which will deflect the beams in a predictable manner.  Your task is to determine the placement of the atoms based on where they exit.

Examples above explain how beams interact with atoms.





0. Every grid in this puzzle will contain exactly four atoms, of which any number can be black and the rest are silver.

No two atoms will ever be orthogonally adjacent within a single grid.



1. If an orthogonal beam approaches a black atom, it will deflect at 90 degrees at the point immediately diagonal to the atom (red)

If a diagonal beam approaches a black atom, it will deflect at 90 degrees at the point immediately orthogonal to the atom (green)

If a beam approaches a silver atom, it will deflect at 135 degrees at the point immediately orthogonal (pink)

If none of the above happen, the beam continues to travel in a straight line (blue).  Note that a diagonal beam can pass any atom diagonally adjacent to it.



2. A beam will be affected by every atom it approaches, in sequence.



3. A beam hitting a black atom head-on will be absorbed, and not exit the box.  This is the only way a beam can be absorbed, and is denoted by a black beam.

A beam hitting a silver atom head-on will be reflected out the same hole it entered (because silver is reflective.)  There are two other ways a beam can be reflected.  All reflections are denoted as white beams.



4. If a beam enters the grid adjacent to an atom in such a manner that the path it must have taken to get there is impossible (i.e. it would have deflected earlier; see diagonal lines) it is immediately reflected.  There are three cases of impossible beams in this puzzle and all three are shown.



5. If a beam reaches a point in which one atom would absorb it and another would deflect it simultaneously, absorption takes precedence.  Depicted is the only such case.

Any other time distinct atoms would have a beam behave in different manners simultaneously, the beam is reflected.  There are seven cases of this behaviour, but only two are shown above (you may ask for the rest if you can't figure them out on your own.)