Permutations of an array of arrays of strings

Question

I simply cannot wrap my head around how to solve this problem and after a thorough search on Google with no results, I turn to you with hopes of a solution.

Given the sa

Answer 1

for ($i = 0; i < sizeof($Type); $i++) {
  for ($j = 0; j < sizeof($Size); $j++) {
     for ($k = 0; k < sizeof($Colour); $k++) {
       echo $Type[i] . $Size[j] . $Colour[k];
     }
  }
}