Changing Cable Units — Ferrule Dimension Variability

I am planning on changing my brake and shifter cables on my Bianchi Intenso with 10 pace Shimano 105 group. I can verify that the brake cable is commonplace 5mm and the shift cable is commonplace 4mm, however there appear to be some variances in O.D. for the brake cable ferrules. My components bin has brake ferrules to suit 5mm brake housing however O.D.s are 5.5mm on some and 5.9mm on others.

The rationale the O.D. is necessary is that the CF body has inside cables and the place the ferrules must ‘plug in” to the body, they should be the smaller exterior diameter model. Additionally, the OEM ferrules, Bianchi applied are silver alloy and for seems I feel I would favor to make use of a black ferrule, possibly plastic. Apparently, Bianchi used black ferrules for the shifter cable housing.

If I order Shimano cables and housing, which I’m prone to need to use, what can I count on to get for ferrules?