Solution for Puzzle 42

Put the purple with the other purples between the blues on the bottom right row to clear.
Put the red with the other reds on the bottom left row between the purples which will join this row up to the next one.
Change the blue balls to white with the reflector.
Put the purple ball with the other purples on the left row to clear this row.
Change to red ball and put it with the other reds on the left top row between the yellows which will join this row with the other row at top.
Change to yellow reflector and change the white balls to yellow balls.
Change to red reflector and change the yellow balls to red balls.
Change to red ball and put it between the purples on the right bottom row which will clear.
Clear the purple balls with the purple ball which will leave one remaining white ball which you don't have to use.
All finished!