You have already applied custom CSS it seems , you need to change the below custom CSS –
.lvca-portfolio-wrap .lvca-portfolio .lvca-portfolio-item .lvca-project-image .lvca-image-info .lvca-post-title a {
color: #ffffff !important;
}
And you can use the below for changing the hover brightness –
.lvca-portfolio-wrap .lvca-portfolio .lvca-portfolio-item .lvca-project-image:hover img {
-webkit-filter: brightness(60%);
filter: brightness(60%);
}
And to change the color of category terms pls use this –
.lvca-project-image .lvca-terms a {
color: #000 !important;
}