How to remove lines or change colour?

Hi Daniel,
thank you for Minimatica. It´s a great theme.
The slider works perfect (charlymay.com).
Now I have still a little problem on the following pages with some lines on top of the navigation bar.
I use NextGEN as gallery. At the end of the pages with galleries appears a small line. I think that line belongs to the comments section. How can I remove that line, or change the colour into white?
On the other pages appears a second and longer line. Is it possible to remove that line or change the colour into white?

I removed:
1) search bar (deleted, description on the theme support)
2) comments are closed (How to delete “Comments are closed”, description on the theme support)
3) written by, on, filed under (removing post details, description on the theme support).