Black Roux, Bad Gumbo

So I was trying to make gumbo before I got sick, and the most interesting and challenging thing about gumbo appears to be the roux. As the wiki says, it's flour added to hot fat that is stirred constantly until it the raw flour taste is gone and it reaches the desired color. There is apparently a yin-yang between thickening power and distinctiveness of flavor... that is, your "white" roux doesn't taste like anything, but really thickens your soup or whatever... while a very dark/brick roux has a strong and distinctive flavor but doesn't really do much thickening at all. You often uses a lighter roux to thicken a gravy or something where the juices of what you are making the gravy from should be dominant, but in a gumbo it's cooked until it's very dark. Making such a dark roux is fairly challenging because you have to cook it for such a long time, stirring constantly, without burning the flour or letting the oil get too hot. Some people cook it on quite a low heat and stir for an hour minimizing risks of burning, while others cook it on a high heat and try to get it done in like 10 minutes. I decided to go for the middle road of medium heat and 20-25 minutes of stirring.

Early on it looked like this:

It should never look like this... I seem to have taken it past the dark/brick stage on to the black stage:

I didn't realize at the time, of course, since I've been to New Orleans all of once in my life and certainly am no expert on Cajun/Creole cooking... nor on regular cooking either, but let's set that aside... and I was working from a cookbook description that said things like "cook to the color of an old copper penny" which seemed pretty vague at the time. After looking at some pictures on the web I get it more now, and know what I'd be looking for when I try it again. Anyway, I went on to cook the gumbo with a black roux... completely oblivious... and, to be honest, didn't even notice it was burnt... though I didn't find it particularly impressive either. I plead the fact that I was getting sick at the time, and probably had dead taste buds... but anyway, there were numerous problems with my gumbo attempt, beyond the roux, which I plan to fix for my next attempt.

Things to fix

1. I only went to Shaws to get my shrimp, and thus they were frozen and mostly peeled, leaving me only the tails to make my shrimp stock. Weak. I need to make the extra effort and get to one of the two excellent fish markets in East Cambridge, even though they are out of the way to get fresh shimp with their heads still on.
2. I also didn't get andouille sausage, and went with kielbasa which is pretty damn bland in comparison.
3. Make the roux right.

Hopefully in the future I can report back with something that is a little less of a fiasco.