White Roses drop from 'Rewards'?

[SeroZeroes]

I'm in dire need of the last white rose to make my gem. I have done all the dailies from dungeons that drops it. Now all that is left is spending another 1999 nc coins to get a duplicate valentine outfit just for the 12 white rose.

 

I read on website that white roses seems to drop from 'rewards', anyone seen them drop elsewhere other than the dailies?

[Kromede]

Only dungeons daily reward.

I didn't pay attention to seasonal event so when I noticed the gem/outfit from the event....I was too late to farm anything hahaha, well until next year if I still play this game :P