Same beer, Different color

I recently brewed a AG Kolsch. At bottling time, I split it into two mini-kegs, force carbing the first, and putting a co2 blanket on the other and set it aside for about a month. The first was a nice light tasting classic fizzy yellow beer, with decent clarity. I just tapped the second one today, and found a light-red grapefruit color. The beer tastes the same although I need to carb it up a little more, but the color is very different. What could cause this?

Maybe whatever was in the minikeg before the beer? Maybe your kid "helped" out by dropping an easter egg dye tab in there? Maybe you had a cut and some blood got in there? Possibly you half blessed it and converted part of it to wine?

Ok if I keep going it's going to get worse.

I would be that it was some contamination in the keg from a previous batch.

How is the clarity on the second one? If you racked into it second, it could be that you transferred more of the trub, and it hasn't all settled out yet.

It could be slightly oxidized. Nothing to worry about though.

Both kegs had the same beer prior, and both were cleaned well. The beer sat in the primary for a month, no secondary. The second keg was stored around 72 degrees for a month in my beer closet. The second keg was stored in the fridge for three days before tapping it. The second keg has similar clarity to the first, similar flavor to the first, just not the same color. I also have a growler of the same stuff stored away. I am reluctant to open it just to see the color, but that will be the test of whether it was the beer or the container.

Has it been in any amount of sun?

Only the sun that leaked in around the keg seal

Was keg#2 still under pressure when you went to put it on tap? Did you purge the O2 from that keg? Is there a chance that somewhere in the process of racking and storing of keg #2 that you introduced a greater amount of O2 into keg #2 in comparison to keg #1?

I was recently reading Bamforth, and he states that a change in color is a sign of oxidation, and that it could show up before other (taste/smell) effects of oxidation.

What temp are you serving keg#2? I'd be curious to let it warm up to the mid 50's to taste-- doing this might allow you to perceive some other oxidation type side effects to corroborate a color change due to oxidation that might not be showing if you are tasting/drinking the beer at colder temps.

Just something to think about.

Good luck.

I purged the keg and topped it up to 20# and sat it aside for a month. It was still under a little pressure (and minimally carbed) when I tapped it. I am serving at about 40 degrees. When I get back to town, I will warm up a glass and taste it.