the live racers on side is white background i have tried using the code from .com but still goes white background
From the code colours are set by class light:
Testing (remove that class manually or change to dark):
From the menu code it's clear that this class is generated by liveracers script itself. At first you should change code - maybe there is something like theme - on liveracers.com site and replace your code inserted in menu.
Because this issue you can't use core custom menus directly. I made simple plugin for this.