The plugin doesn't have an interface.

How does it work:

Select some nodes you want to update. When nothing is selected, all nodes on the page are updated. Launch the plugin. The plugin will identify color variables with matching names associated with local variables, and apply them all at once based on your selection. It will be highlighted if a layer's variables have not been updated.

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The plugin may slow down if there are too many nodes on the page. If this is the case, try selecting nodes instead.