I was deleting the message too early for the grayscale to work

cogs/fun.py

@@ -438,8 +438,6 @@ class Fun(Cog):
         """Display grayscale version of image uploaded"""
 
         if ctx.message.attachments:
-            await ctx.message.delete()
-
             for attachments in ctx.message.attachments:
                 attach = await attachments.read()
                 image = Image.open(io.BytesIO(attach)).convert('LA')
@@ -449,6 +447,7 @@ class Fun(Cog):
                 image.save(file, format='PNG')
                 file.seek(0)
 
+                await ctx.message.delete()
                 # Send Grayscale Image
                 await ctx.send(file=discord.File(file, "gp.png"))
         else: