[Plugin: Contact Form 7] Drop-down Menu – Change "include_blank"

When I select “insert a blank item as the first option,” the field displays: “—“. Is it possible to change “—” to something else?

Example: [select* menu-323 include_blank “Red” “Blue”]

Could I change “—” to “Color”?

http://wordpress.org/extend/plugins/contact-form-7/