The other theme was different and better, so let's stick to the kdl file

home-manager/shared/shell/zellij.kdl

@@ -0,0 +1,31 @@
+session_serialization true
+theme "catppuccin-macchiato"
+
+themes {
+    catppuccin-mocha {
+        bg "#585b70" // Surface2
+        fg "#cdd6f4"
+        red "#f38ba8"
+        green "#a6e3a1"
+        blue "#89b4fa"
+        yellow "#f9e2af"
+        magenta "#f5c2e7" // Pink
+        orange "#fab387" // Peach
+        cyan "#89dceb" // Sky
+        black "#181825" // Mantle
+        white "#cdd6f4"
+    }
+    catppuccin-macchiato {
+        bg "#5b6078" // Surface2
+        fg "#cad3f5"
+        red "#ed8796"
+        green "#a6da95"
+        blue "#8aadf4"
+        yellow "#eed49f"
+        magenta "#f5bde6" // Pink
+        orange "#f5a97f" // Peach
+        cyan "#91d7e3" // Sky
+        black "#1e2030" // Mantle
+        white "#cad3f5"
+    }
+}

home-manager/shared/shell/zellij.nix

@@ -4,6 +4,12 @@
     # TODO find specific settings for vscode to avoid
     enable = true;
     enableZshIntegration = true;
-    catppuccin.enable = true;
+  };
+
+  home.file = {
+    "zellij" = {
+      source = ./zellij.kdl;
+      target = ".config/zellij/config.kdl";
+    };
   };
 }