Thank you so much!!

You are really helpful!!!

Just if someone need it, this is the code to change the color of the arrow aside the porfolio image!!

.sh-gallery .slick-prev,
.sh-gallery .slick-next {
color: #fff
}

.sh-gallery .slick-prev:hover,
.sh-gallery .slick-next:hover {
color: rgba(255,255,255,0.4);
background-color: rgba(255,255,255,0) ;
}