How do you create slanted/angled sections?

How do you create slanted or angled sections on template Pacific.

i would like to add gradient and slanted section.

Also my header navigation is transparent - how do i keep it transparent - and have what ever color i want when i scroll because now its using what ever color the background is. i want it to be transparent when static at the top but white when i scroll

Really need help with this.

apperciate it alot with help on this one

Example 

to change header color on scroll, add this to Home > Design > Custom CSS

/* on scroll header color */
.shrink {
    background: white !important;
}
/* on scroll header elements color */
.shrink * {
    color: black !important;
}

Kinsta used background image. You can add background image for your section