When you say "Rust enums are also enums", that's not true in general. What is true is that _some_ Rust "enums" (like your `Colour` example) can be represented a

When you say "Rust enums are also enums", that's not true in general. What is true is that _some_ Rust "enums" (like your `Colour` example) can be represented as traditional enums. You don't prove a universal quantification with a single example.