Hi, I have a Diane messenger in Bleu de Cocagne, if you go back in the thread you can see some photos that I’ve shared of how the patina has developed. It gets darker, with purplish undertones in some lighting. I believe it will continue to darken as I use it. It definitely has some scratches, especially the flap and the underside of the flap (when I scrabble around in it one-handed !), but the marks soften with time and use. You can rub the scuffs gently with a soft cloth to smooth them and they kind of melt back into the leather. Like
@bagnut1 said, I too love the marks on heritage leather.
I’m a big natural leather fan, I have some barenia pieces from Hermes and Moynat that are now a really dark brown, and a beautiful olive novo nappa from Ramesh-era Moynat that has turned a deep grey-green. This is the same leather as Jospeh Duclos heritage, with Ramesh making the choice of leathers in both cases, so its safe to assume they will develop similar patinas.
The speed at which the patina will develop depends on how often you use it, how you handle it and any lotion or other products you may use. Hand creams etc are really not an issue (they accelerate the patina), but I have made the mistake of getting hand sanitizer on novo nappa and that is definitely a no-no

!!!
Hope this helps.