Each flower has its own meaning. The same applies to the shades of these colors. I found http://el7set.es/art/46859/el-arte-de-regalar-rosas-simbolismo-detras-de-los-diferentes-colores-de-rosas-y-su-significado this interesting article, I am sure you will like it too. You can find out which color of roses is best suited for which occasion!