Enum values can contain futher values. Use pattern matching to access.

src/main.rs

@@ -1,21 +1,21 @@
-enum ColorSpace {
-    RGB,
-    RGBA,
-    CMYK,
-    YUV,
+enum Color {
+    RGB(f32, f32, f32),
+    RGBA(f32, f32, f32, f32),
+    CMYK(f32, f32, f32, f32),
+    YUV(f32, f32, f32),
 }
 
-fn color_space_to_string(color_space: ColorSpace) -> String {
-    match color_space {
-        ColorSpace::RGB => String::from("RGB"),
-        ColorSpace::RGBA => String::from("RGBA"),
-        ColorSpace::CMYK => String::from("CMYK"),
-        ColorSpace::YUV => String::from("YUV"),
+fn color_to_string(color: Color) -> String {
+    match color {
+        Color::RGB(red, green, blue) => String::from("RGB"),
+        Color::RGBA(red, green, blue, alpha) => String::from("RGBA"),
+        Color::CMYK(cyan, magenta, yellow, key) => String::from("CMYK"),
+        Color::YUV(y, u, v) => String::from("YUV"),
     }
 }
 
 fn main() {
-    let color_space = ColorSpace::RGB;
+    let color = Color::RGB(1.0, 0.0, 0.0);
 
-    println!("Color Space: {}", color_space_to_string(color_space));
+    println!("Color: {}", color_to_string(color));
 }