Aero Precision Cerakote Question

[hg8057]

I'm in the middle of a pistol build using Aero Cerakoted receivers. I had a local dealer order the lower some time ago and have gotten it fully assembled. I ordered an upper direct and it arrived yesterday. The shine and shade are markedly different between the two. The upper is lighter in shade (both Olive Drab) and has no shine whatsoever. The lower is darker with a satin-like shine to it. I contacted Aero and my impression is that they're being kind of fussy about the whole thing. They said I could return it for exchange but would be subject to a 10% exchange fee. Really? The reason I'd like to exchange the upper is that their own cerakoting isn't even close in the same color. Plus, if they deem the upper to have been "used" (has only been put on the lower to check fit) it would be shipped back to me at my expense. I'd rather not pay to have it shipped 3 times and possibly pay an exchange fee. (Edit: both receivers were purchased stripped)

All of this leads me to my question:

Is there anything that I can do to slightly darken and shine the cerakoted upper? It doesn't have to be perfect, just closer than it is now.