XF 2.0 Changing colors in 'attach files' button

[wands]

I need some guidance regarding button colors.

How can I change the background color of the attach files button? I want it to match the other two buttons on the right.



Also is it possible to change the color of those automatic text avatars and make it the same for all letters. I am assuming each letter gets its own background color (for example green for wands)

Thank you!

 

[S Thomas]

extra.less template:

.button--link.js-attachmentUpload.button.button--icon.button--icon--attach {
   background: black;
    color: white;
    border-radius: 0px;
    border: none;
}

The other one needs some coding.

 

[wands]

Thank you.

 

[welington]

you helped me, thank you