One from worst variants is if you will use such stuff: to present as gift pair number of flowers. It funeral symbol. Like 2, 4, 6, 8, 10 etc....it is symbol of funral ritual used exactly for this.
Then color meanings.
One from stuff is used to reject guy or girl without words told and meas " we never will be together ".....it is used is if in general this person is acceptable and might be even best friend and therefore such stuff is used to get know that ," there will not be bed pleasures with me ". Like this.
We are learning about ppl in some asia, africa and so on cos " we should know " etc and in not rare cases don't care about stuff in europe and then wonder why etc...