For anyone looking for blue rose

snow witch drops.

lolroses.

You could also try killing those Jr Sentinel things.

wtp? did that drop from them?

WHAT THE HELL? How did you get that ring!

Edit: A ring that came with BB simillar to Welcome Back ring but with stats and tradable through storage

Not my picture. No idea where the ring came from.

Jr. Yeti's also drop Blue Rose. Found one while walking to Zak.

I found one from a Yabber Doo while helping someone do the Scarga Pre-quests

I'm going to say everything drops every rose (Blue from Slime). Even PQ monsters that rarely drop anything will drop roses, case in point the Blue I got from HPQ or the Reds and Yellows from PPQ.