diff -r a5667285680d src/video/SDL_surface.c
--- a/src/video/SDL_surface.c	Tue Nov 08 01:12:54 2016 -0500
+++ b/src/video/SDL_surface.c	Tue Nov 08 18:51:54 2016 +0100
@@ -970,13 +970,32 @@
         }
 
         if (set_colorkey_by_color) {
-            /* Set the colorkey by color, which needs to be unique */
-            Uint8 keyR, keyG, keyB, keyA;
+            SDL_Surface *tmp;
+            SDL_Surface *tmp2;
+            int converted_colorkey = 0;
 
-            SDL_GetRGBA(surface->map->info.colorkey, surface->format, &keyR,
-                        &keyG, &keyB, &keyA);
-            SDL_SetColorKey(convert, 1,
-                            SDL_MapRGBA(convert->format, keyR, keyG, keyB, keyA));
+            /* Create a dummy surface to get the colorkey converted */
+            tmp = SDL_CreateRGBSurface(0, 1, 1,
+                                   surface->format->BitsPerPixel, surface->format->Rmask,
+                                   surface->format->Gmask, surface->format->Bmask,
+                                   surface->format->Amask);
+
+            SDL_FillRect(tmp, NULL, surface->map->info.colorkey);
+
+            tmp->map->info.flags &= ~SDL_COPY_COLORKEY;
+
+            /* Convertion of the colorkey */
+            tmp2 = SDL_ConvertSurface(tmp, format, 0);
+
+            /* Get the converted colorkey */
+            memcpy(&converted_colorkey, tmp2->pixels, tmp2->format->BytesPerPixel);
+
+            SDL_FreeSurface(tmp);
+            SDL_FreeSurface(tmp2);
+
+            /* Set the converted colorkey on the new surface */
+            SDL_SetColorKey(convert, 1, converted_colorkey);
+
             /* This is needed when converting for 3D texture upload */
             SDL_ConvertColorkeyToAlpha(convert);
         }