Beautiful face!

It's a real shame about the annodizing, though. There is a solution.

Your welding shop is using the wrong filler rod. They must try for a better match of the base material. This is a very common problem- meaning that even the welders don't know what's going on.
Your parts are likely to be 6061 (a very common alloy).
Most shops weld with either 4043 or 5356 welding rod.
4043 flows better and is easier to make a nice looking weld with, because the major alloying constituent is silicon.
5356 has got some small amount of magnesium in it and makes a stronger weld.
6061 is an alloy containing both silicon and magnesium.
I can't remember all the details, but it's worth a little more research.
I learned about this a long time ago- about 15 years.

At any rate, welding the 6061 with one or the other filler ends up giving you very bad results after annodizing.
Sorry, I can't remember which is which... whether it's the magnesium that's oxidizing differently or the silicon.
Ask your shop which filler they use and suggest they try the other.
They might not be so organized as to know which they used- or have only one on hand but not the other.

A poor reply from a welding engineer, but I haven't been in that field for a while now.