163550

We worked out that it's better to go as Player 2 as you can always win with the right move. If Player 1 starts with colouring in 1 petal, Player 2 will need to colour in 2 petals that are opposite (leaving 2 blank petals around Player 1s). If Player 1 starts with colouring in 2 petals, Player 2 will need to colour in 1 petal that is opposite (leaving 2 blank petals around Player 1 again). We quickly realised that we needed to split the last 2 petals left so that one player couldn't colour both in at the same time. Therefore it is always better to go second as you can create this scenario.