Where do you stand on roux color for cajun cooking?

I just made jambalaya and of course roux is an essential ingredient. I took mine to the color of like a semi sweet chocolate. I have never gone darker than that because I'm worried it might negatively affect the final flavor of the dish.

How dark do you go?

Have you ever got to the point where it's almost charred? What did that do for the flavor of the dish?