fix color pretty printer to show alpha at the right time

src/adam/adam.ml

@@ -195,10 +195,10 @@ module Color = struct
     in
     if a < 1.0 then
       let rgb = hex (r / a) (g / a) (b / a) in
-      Format.fprintf ppf "#%06x" rgb
+      Format.fprintf ppf "#%06x;%.2f" rgb a
     else
       let rgb = hex r g b in
-      Format.fprintf ppf "#%06x;%.2f" rgb a
+      Format.fprintf ppf "#%06x" rgb
 
   let invisible () = { r = 0.0; g = 0.0; b = 0.0; a = 0.0 }
   let black ?(a = 1.) () = { r = 0.0; g = 0.0; b = 0.0; a }