User blog comment:PuffDragon/On the Red Rose lyrics/@comment-7713314-20130402043756

Ruby's line could mean that she's suffering guilt over something. Or perhaps she's following the example of someone who came before her. Regardless, it certainly seems to be a fixation of some sort.

I agree with Reverse Vampire about Weiss. Perhaps she is, or feels, isolated from others due to her own position, leading her to yearn for more in her life.

The same for Blake.

For Yellow... Her symbol looks like a heart that's on fire. Maybe her abilities are somehow based on heat, or she has a 'fiery' personality.