is there a way to assign one 'id' (subject) to one colour for xyplot to keep the co-ordination for different xyplots? also how to increase the number of colour for a xyplot that has more than 7 'id' (subjuects) I found one previous message but did not understand what he did. I attached a sample dataset. http://www.nabble.com/file/p12855016/graph17sep07.csv graph17sep07.csv the codes that I used were: p1 = xyplot(protein~day|breast, data= test) p2 = xyplot(lactose~day|breast, data= test) I want to keep the same colour line for each id in both graph thanks -- View this message in context: http://www.nabble.com/assign-one-%27id%27-one-colour-for-xyplot-tf4507453.html#a12855016 Sent from the R help mailing list archive at Nabble.com.