Rose is cosidered one of the hardest flowers to paint, so when I made it the main task for me was to show different petals.
Since the rose was white shadows looked more brown and beige and I started with that colour. Then I thought I can try to make reflexes with green from leaves and blue from the sky. And finally i decided to add violet to make shadow really shadow.
And that's how the rose turned out to be a dirty cabbage :)
Still everyday work and experiments are worth trying.