Getting Categorical Slots from Lookup Tables Possible?

Hi,

I’m using Rasa 3.1, and I have a really specific use case I need help with. It’s something like this.

Imagine I have a form artist_form where I am trying to find out various things: name, favorite color, etc.

In my slots, color is a categorical value so I can use the Branching Logic Feature so I can change the flow after the form. Imagine that the slot categorical values are red, green, and blue.

If the user says “magenta” as their favorite color, how do I convert the color entity to red? I considered synonyms, but because it matches exact cases, would I need training examples with “magenta”, “MAGENTA”, “Magenta”, and so on? I was wondering if there was a way to use lookup tables , or even regex patterns to handle all the cases and map it directly to the color slot value.

If anyone can help please let me know!