Accessing an event's attributes in Pinpoint template through front-end using Amplify JS

I have an AWS Pinpoint application.

On the web app front-end, I can trigger an event as follows:

   await record('my.event', {
     attributes: { color: 'red', size: 'large' },
     immediate: true
   })

In Pinpoint, I can create a campaign with an email template to send an email to the user whenever my.event is triggered. I'm able to access the endpoint attributes such as {{User.UserAttributes.GivenName}} or {{Attributes.Preferences.Hats}}.

However, I'm not able to access the event attributes (color, size) in the above example in the email template.

Is there a way to do this?

It seems like you can only filter the events to determine whether the campaign email should be sent (e.g., send only if color==='blue').

I suppose that I could temporarily update the endpoint Attributes before triggering the event, but that is not preferred as it requires an additional call.