Visibility of midi note preview in edit mode

Compared with version 8 the transparency of the preview of a midi is so i can hardly see it. Mainly when not zoomed in, but even then i got hard times.
I went through Preferences, Appearance, Colors, both Items and Transparency, but can’t find if i can change it at all.
Is there a way to change it, to make it more visible?

As it is hard to describe, i use a picture what i mean.

transparency