How to change theme Content?
 

How to change these colors in content?
Where?

\include\templates\themes_name\style\style.css

the style.css you can modify it

Exactly where in style.css is content colors?

a trick to find the colours is print the screen like that then paste it into Photoshop or a similar program, then using the colour picker find the html code for the colour in the corresponding style sheet.

Didn't did a trick... how to change these colors like that:
Background is black
Words is in white

style.css
 

style.css look for

table, td, thead, main .left

that should do it