Changing color on targeted font

Site URL: http://www.thomasprudhomme.com

Hello, 

here is my website-> http://www.thomasprudhomme.com 

in my case i can't change the "BOOK ONE" and "FACETIME LOOKDOWN" in any colors in fact. I wanted to change to white for those two but I want to keep the titles at the top in black

thank you for your help, 

Anyone? 🙂

Hi. Sorry for the late reply. Add this to Home > Design > Custom CSS

.grid-item h3.portfolio-title {
    color: red;
}