Changing the colour of a rose

We had a white rose and decided to do an experiment to see if we could change its colour from white. We know that plants suck up water through the xylem, so what will happen if we put some dye or food colouring in? We split the stalk into 4 parts. The food colouring colours that we had were black, yellow, and green. Each of the 4 parts were put into different containers. One was just put in water. We could see the colour changes through the veins in the petals. We thought that was cool.
The first photo is at the beginning, and the second one shows some changes. The little white bud at the side went almost completely black. You can see that in the photo.