How do I change default file text color on the left panel while being able to customize each?

What I’m trying to do

I want to change the default color of the file name when you create a new file listed on the left panel. (Under Anu theme.) And it won’t override the plugin: file color.

Things I have tried

My rainbow color function is turned on. I searched and managed to change the font color using:
.nav-file-title-content {

but it changes all colors and I can’t set each color by using the plugin file color.

Can anyone help me? Thanks!