@aparma: Thank you for your interest on our JA Fixel template. We would like to answer your questions in detail as follows:
<blockquote>Is it possible to change the size and colors of borders of the elements in the Grid?</blockquote>
In fact, our developers do not define the size and color of grid borders. It is just the background color of content area with the empty distance between 2 grid items.
You just need to change the background color of content area by creating a custom.css file at templates/ja_fixe/css/ path and add this rule:
.fixel-grid {
background-color: white;
}
<blockquote>I would like to increase the distance between the modules in grid.</blockquote>
The distance between grid items was divided equally by the Masonry javascripts inside templates/ja_fixel/js/script.js file. You should have knowledge of javascripts to modify the parameters of this function.