How do you change the header/footer colour on a single page?

@tuanphan thank you thank you!

while i have you here, please, how do I reduce the heading size of that one section in mobile view https://jeanine-thompson.squarespace.com/speaking "August '22" I need to make this smaller

Thank you!!

@tuanphan 

15 hours ago, Iwan said:

@tuanphan 

Try this CSS code

@media screen and (max-width:767px) {
h2.list-item-content__title {
    font-size: 5px !important;
}
}