XF 2.1 How to change the color of highlighted background and vertical bar in a quote?

[Ottavius]

As shown in Blue Arrows.
(I took a random image and screencaptured it to use it as sample)

 

[Paul B]

The class is in the panel on the right - you can see where I have changed the colours to orange and green.

You can use the extra.less template to override the defaults.

 

[Ottavius]

Thanks, I was able to find the extra.less template, but it is empty. Can you please tell me what codes to put in?
Say, I want Blue for vertical bar and Orange for background

 

[Paul B]

Actually, that screenshot is for 2.2.

You have a 2.1 prefix on this thread so it would be:

.bbCodeBlock
{
    background: orange;
    border-left-color: blue;
}