Meanings behind Flowers and their Colors

http://www.angelfire.com/journal2/flowers/l.html

Connotations of the Blue Lotus Flower in Buddhism

This is the symbol of the victory of the spirit over the senses, of intelligence and wisdom, of knowledge. It is always represented as a partially opened bud, and (unlike the red lotus) its centre is never seen. It is the lotus of Manjusri, and also one of the attributes of Prajnaparamita, the embodiment of the 'perfection of wisdom'.

Source:
http://www.buddhanet.net/e-learning/history/b_lotus.htm