Offcourse,
this is for titles, also style.css file:
.portfolio_item .overlayed .overlay .overlay_title {
font-family: Roboto;
font-size: 20px;
color: #fff;
font-weight: 300;
margin-top: 50%;
margin-bottom: 0;
}
in here you can change color, font size and everything else.
This is for categories:
.portfolio_item .overlayed .overlay .portfolio_item_tags {
font-style: italic;
margin-bottom: 0;
}
just find this code in style.css and add in here whatever you want.
Regards