Hi,

1/ For featured slider, you can check options for it via Customize > Colors for Featured Slider.

2/ For featured categories "Career" & "Resources", please add more this code to Customize > Custom CSS to change it:

\
.home-featured-cat-content.style-14 .penci-image-holder:after{ \
background: -moz-linear-gradient(top, transparent 50%, #fff 100%);\
background: -webkit-linear-gradient(top, transparent 50%, #fff 100%);\
background: -o-linear-gradient(top, transparent 50%, #fff 100%);\
background: -ms-linear-gradient(top, transparent 50%, #fff 100%);\
background: linear-gradient(to bottom, transparent 50%, #fff 100%);\
}\
.home-featured-cat-content.style-14 .first-post .magcat-detail h3 a, .home-featured-cat-content.style-14 .first-post .magcat-detail h3 a:hover{ color: #111; }\
.home-featured-cat-content.style-14 .mag-meta{ color: #414141; }\

Best Regards,

PenciDesign