Removing Color Section Background Image on Mobile

Hello,

I’ve been crawling these forums for a while and trying the various solutions presented. I’m trying to remove the fixed background images on the page noted below when viewed on a mobile device.

So far adding the following to my Quick CSS:
@media only screen and (max-width: 989px) {
#hide-bg-mobile{
background-image:none !important;
}
}

And then assigning the hide-bg-mobile ID to the color sections results in the background images disappearing when my browser window size is reduced, but the images still appear on both Apple and Android devices.

I’ve supplied the URL below, as well as the login I’ve given you guys for tickets in the past. Thanks for your help!