diff --git a/src/cli/cli.rs b/src/cli/cli.rs
index b0cccda..df68c6e 100644
--- a/src/cli/cli.rs
+++ b/src/cli/cli.rs
@@ -359,7 +359,8 @@ pub fn build_cli() -> Command<'static> {
                                            "lab-a", "lab-b",
                                            "oklab-l", "oklab-a", "oklab-b",
                                            "red", "green", "blue",
-                                           "hsl-hue", "hsl-saturation", "hsl-lightness"])
+                                           "hsl-hue", "hsl-saturation", "hsl-lightness",
+                                           "alpha"])
                         .ignore_case(true)
                         .required(true),
                 )
diff --git a/src/cli/commands/color_commands.rs b/src/cli/commands/color_commands.rs
index f215fa2..3f6e7c0 100644
--- a/src/cli/commands/color_commands.rs
+++ b/src/cli/commands/color_commands.rs
@@ -181,6 +181,11 @@ color_command!(SetCommand, config, matches, color, {
             }
             Color::from_lch(lch.l, lch.c, lch.h, lch.alpha)
         }
+        "alpha" => {
+            let mut hsla = color.to_hsla();
+            hsla.alpha = value;
+            Color::from_hsla(hsla.h, hsla.s, hsla.l, hsla.alpha)
+        }
         &_ => {
             unreachable!("Unknown property");
         }