Possible to use default:shortcode_attr with wpcf7_add_form_tag custom tag?

Hello!

I’m trying to use one of the attribute values in my custom tag I created with wpcf7_add_form_tag

For example, I created a custom attribute “color” which I can pass into the form like this:

[contact-form-7 id=”7258″ title=”Replay Video Form” color=”red”]

But now I want to use that in the form somehow, and I can’t figure out how to build the filter function to output an attribute value.

[customtag color default:shortcode-attr]

I can create the customtag and access the color name, but it won’t set a default value.

Help?