Subject: Why do dyes travel at different rates on flower experiment

My Mom and I put 2 white carnations into 4 tall glasses of water with dye. One 
red, Blue, Green, and Yellow.  All sat on the counter together in front of the 
window.  We cut the stems on all the flowers and added equal amounts of dye to 
each glass.
The Yellow changed colour the fastest - 1 day, the blue was next - 2 day, the 
red next- day 4 and the green was very slow - 6 days.  I even re cut the green 
and added more drops on day 4 and still it took almost 2 more days to show 
colour.
Why do different colours take longer to show?
ps, I had a celery stalk with leaves in each glass also and they absorbed 
colour at the same time line as the flowers. we used food colouring.

Re: Why do dyes travel at different rates on flower experiment