can I define the look of the horizontal ruler?
I want it to be a thin line with little arrows at both ends.
And I want to define the color.
… ah, and could you please help me with my further problems with the page titles and the contact form borders?
Please post the link to your page where you have horizontal ruler and we can provide you custom CSS to change the color but to customize it, you are going to need to hire a freelance developer for that kind of customization as it is beyond the scope of support we can provide. You can also request quote here.