Solution

Colour Clue

Reveal

All of the patterns of coloured squares have a diagonal line of symmetry - a mirror line - to them. Since the puzzles are symmetrical, it might be an idea to look for solutions that involve symmetry - pairing pieces you put down with their mirrored pieces on the other side of the mirror line. Some of the number patterns also have a line of symmetry to them - can you see where the prime numbers are on the board?