Into impls for Colour (are these necessary?)

src/colour.rs

@@ -1,5 +1,7 @@
 use std::fmt;
 
+use image;
+use image::Rgba;
 use serde_derive::{Serialize, Deserialize};
 
 #[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
@@ -37,6 +39,18 @@ impl Into<Vec<u8>> for Colour {
     }
 }
 
+impl Into<image::Rgba<u8>> for Colour {
+    fn into(self) -> Rgba<u8> {
+        Rgba::from([self.red, self.green, self.blue, 255])
+    }
+}
+
+impl Into<[u8; 4]> for Colour {
+    fn into(self) -> [u8; 4] {
+        [self.red, self.green, self.blue, 255]
+    }
+}
+
 #[cfg(test)]
 mod test {
     use crate::Colour;