mouse hover hightlighting

Hi,

I'm hoping someone can help me with this. If I have an array or a string, going over more then 1 line (see below), when I hover the mouse over it, the array element gets highlighted. I'd like to change the colour of this highlight, but cannot seem to find it in the settings. Can someone please tell me where to find it. Thanks in advance.

e.g.

[
     'template_id' => 2,
     'entry_type_id'=> 1,
     'entry_ref' => '3',
     'text' => 'long bit of text over several lines to illustrate'
          .'what it is that I am talking about (hopefully)',
     'order' => 1
],