Question cannot get rid of blue

Anyone has any idea how to change that blue left border and the background? That's the text between the code tag.

I haven't see the blue border you refer to but I think the CSS that affects this is here:

#Kunena div.kmsgtext pre, #Kunena div.kmsgtext code {
border-color: #BFC3C6 #BFC3C6 #BFC3C6 #F4A94F;
font-family: "Courier News",Courier,monospace;
}

Change the border colours to whatever values you want instead. Add a background-color rule. Does that help?

The hex values there are not blue. Its on the left of the image. The only thing blue in the picture.

As I wrote, I don't recall seeing these colours in the Blue Eagle template. It's possible that these are colours used in some third-party template and you should probably speak to the author of that template. On the other hand, if I've totally got the wrong end of the stick and this is some interesting hidden feature of Kunena that I wasn't aware of, I would be most interested to see this for myself.

As I wrote in another topic earlier today, sometimes we can't solve every kind of customisation simply by looking at a picture (just as it's not always possible for every site administrator to be an expert in CSS either) and it would help if you should provide us with a little more information that demonstrates the issue aside from showing us a picture. Do you think you could do that?

I was thinking that I was the only one seeing the blue. lol
Sorry its my fault, that template did not come with Kunena. Did not think about that. Just found it in kunena.forum-min.css by searching for border-left.
Seems I was lucky.