How to change nebular spinner (NbSpinner) background color

I want to change the background colour for nebular spinner, I am writing below code but it is not working,

@import "[email protected]/theme/styles/theming";
@import "[email protected]/theme/styles/themes/default";

 $nb-themes: nb-register-theme((
  spinner-primary-background-color: white,
   ), default-ltr, default );

Any help on how to do it? Am I missing any imports or am I accessing the theme variables incorrectly? Thanks in advance.

Source: Angular Questions