is it necessary to create a custom theme to add tailwind colors

Hi
I have made a new project with filamentphp v3, and i try to follow this document - https://filamentphp.com/docs/3.x/support/colors

So i just use the FilamentColor::register in my AppServiceProvider.php and then i use it in my custom page blade view file

Somehow this is not working.
Do i need to make a custom theme to use this ??

Please let me know your thoughts.