Use this custom CSS styles:

Everywhere

div.ecwid-productBrowser-productNameLink a,

div.ecwid-productBrowser-productNameLink a:visited,

div.ecwid-productBrowser-productNameLink a:hover,

div.ecwid-productBrowser-productNameLink a:active {

    /* feel free to change the code below*/
    font: normal 12px tahoma, geneva, verdana, sans-serif !important;

    color: #anycolor !important;

}

(do not forget the !important rule)

Grid mode

div.ecwid-productBrowser-productsGrid-productBottomFragment div.ecwid-productBrowser-productNameLink a,

div.ecwid-productBrowser-productsGrid-productBottomFragment div.ecwid-productBrowser-productNameLink a:active,

div.ecwid-productBrowser-productsGrid-productBottomFragment div.ecwid-productBrowser-productNameLink a:visited {

    /* feel free to change the code below*/

    font: normal 12px tahoma, geneva, verdana, sans-serif;

    color: #anycolor;

}

List mode

div.ecwid-productBrowser-productsList-details div.ecwid-productBrowser-productNameLink a,

div.ecwid-productBrowser-productsList-details div.ecwid-productBrowser-productNameLink a:active,

div.ecwid-productBrowser-productsList-details div.ecwid-productBrowser-productNameLink a:visited {

    /* feel free to change the code below*/

    font: normal 12px tahoma, geneva, verdana, sans-serif;

    color: #anycolor

}

Table mode

td.ecwid-productBrowser-productsTable-cell div.ecwid-productBrowser-productNameLink a,

td.ecwid-productBrowser-productsTable-cell div.ecwid-productBrowser-productNameLink a:active,

td.ecwid-productBrowser-productsTable-cell div.ecwid-productBrowser-productNameLink a:visited {

    /* feel free to change the code below*/

    font: normal 12px tahoma, geneva, verdana, sans-serif;

    color: #anycolor;

}