I have added these lines to custom.css
#jp-right{background:#DADAD9}
#top-a{background:#DADAD9}
#bottom-a{background:#DADAD9}
#bottom-b{background:#DADAD9}
#bottom-c{background:#DADAD9}
#bottom-d{background:#DADAD9}
#footer-a{background:#DADAD9}
.tm-toolbar{background:#DADAD9}
.tm-footer{background:#DADAD9}
.uk-container{background:#DADAD9}
html{background: #DADAD9;}
However, the result is still not satisfactory: ckcmed.com.au/mm

Hi there,
maybe you have taken the wrong custom.css file.
You can check it live like this:
ckcmed.com.au/mm/templates/jp-rooms/css/custom.css

Otherwise try to add an "important" to the css code

#jp-right{background:#DADAD9 !important}