IntelliJ -- how to highlight modified files that are under version control

Question

My IntelliJ by default shows the modified files in blue and the unmodified files in black. It's not very sharp contrast so it slightly annoys me.

Where do I configure the appearance? I want to further highlight the modified files under the version control.

[UPDATE]

I found it following the answer, but many features were grayed out... why is that?

Answer 1

Partially covered in the answer by @Marv:

Go to Preferences -> Editor -> Colors & Conts -> File Status, here you can customize the appearance of file names depending on their statuses.

You can also set the background in Preferences -> Appearance & Behaviour -> File Colors if you want more emphasis.

Answer 2

Go to Settings -> Editor -> Colors & Fonts -> File Status, here you can customize the appearance of file names depending on their statuses. See File Status Highlights in the IntelliJ documentation for more information.