What does it mean when you send one red rose and one white rose together?

I foung this meaning and know there are older ones as well.

The use of red and white roses symbolized the sexually active and virginal goddess respectively and set the stage for the later Christian sexual symbolism possessed by the rose. That symbolism survives today in the predominate use of roses at weddings and as gifts for Valentine's Day.

Perhaps then, sending both asks the question... which level of a relationship is the receiver desiring.