Changing color on just one page

Hi,

I thought this would be simple but I'm missing something obvious, for this page
http://www.prosperouspropertiesaustralia.com.au/

I wish to change the menu color to white so I use this

.btLightSkin .menuPort > nav > ul > li > a{
color:white!important;
}

and it works fine, the issue im having is I wish to change it only on the first page and not the others so I put

.page-id-1154 .btLightSkin .menuPort > nav > ul > li > a{
color:white!important;
}

but then that doesn't work.

Any help would be greatly appreciated, thanks.