Extending Tokens Bundles

Use the extends attribute to extend one tokens bundle from another.
To add tokens from one bundle to another, extend the “child” tokens bundle from the “parent” tokens, like this.
<aura:tokens extends="yourNamespace:parentTokens">
    <!-- additional tokens here -->
</aura:tokens>
Overriding tokens values works mostly as you’d expect: tokens in a child tokens bundle override tokens with the same name from a parent bundle. The exception is if you’re using standard tokens. You can’t override standard tokens in Lightning Experience or Salesforce1.
Important

Important

Overriding standard token values is undefined behavior and unsupported. If you create a token with the same name as a standard token, it overrides the standard token’s value in some contexts, and has no effect in others. This behavior will change in a future release. Don’t use it.