budgie bridge color

Question
I have 4 budgies, 2 males and 2 females and they have paired off. One of the female's bridge color has gone from pink to a splotchy darker pinky red color. I have also noticed they are preening each other a lot. I do not have nesting boxes for them yet although I was going to nest them in a few months. Should I be concerned about the bridge color or is it a sign that the she is ready to nest?
Thanks in advance.

Answer
It's perfectly normal for a budgie's cere to change color when they get ready to breed.  It acts as a sort of signal that she's ready to mate. If her colors are bolder and they are preening each other, these are all forms of breeding behavior.  If you want babies, I would get nest boxes.  If you want to wait, that's fine too, but they may start without a box.
Let me know if you have any more questions!
Happy New Year!