Change color font in Header

The (Steakhouse) header contains a logo / text / a line / text./..../....
I'm trying to change te color of the text beneath the logo.
I think i should activate CSS override (see attachment) and fill in some code in the override.css file.
If i'm (newbie in this template) right about this.
1. What code should i write in the override.css file
2. How can i replace the (white) line with something else (.png file)
Thanks

Hello,

Please change the color property for the following selectors:

Code: Select all

#gkHeaderMod h1,
#gkHeaderMod h2

And also border-top-color for:

Code: Select all

#gkHeaderMod h2:before

And finally - background-color for:

Code: Select all

#gkHeaderMod h2:after

Thank you for your reply.
What is the name of the css file in which i should change the color property for these selectors?

The best solution will be adding all CSS changes in template Advanced settings -> Custom CSS code option.