Most common colour is white with purple cross.id say 3-4months.in your case probably another 2months.if u want to wait for pods and scrape them etc it's a shot in the dark.hard to tell exactly but little known fact if u pluck them just before they start to show signs there going to start to flower then this is the point where they have all the morphine in them there going to have and can just be juiced in a juicer to obtain a potent liquid which when dried into a paste is more potent than regular opium gum or they can be boiled like mushies for a potent tea.once they start to pod your past the point of no return and you have to go all the way and score/scrape them as I suspect all the morphine goes from the leaves/stems to to the pods.
Another tip: you got to space them out to get full sized pods.i didn't and had hundreds per square metre and the biggest pod I got is the size of a medium grape.all those thin stems equal small pods.space them out for pods or juice them if growing in tight clusters.
What are the signs that they are about to flower if you don’t mind me asking? Great additional info btw!
I do recall reading some information that sounds similar to what you describe with the morphine content being there before the flowers even form.
-GC