[RGL Griff XV]

https://gyazo.com/258e1199c05056e7eeef4ffa219f69a2
Which Stylevar is the Thread/post title? I need to change the highlight color (selected)

Edit, The text is white after I type something in and the background is black.
Whenever I begin to type something, it then becomes a white bar and I cannot see what I am typing.

[shka]

I don't know if I understood your problem correct. You mean:

click in input-box (in your pic the title field of advanced editor, but also every other input field like login data with your demo account, edit and send a pm ) results to white background and white text?

Your aim: other text color?

There is no stylevar for. In template "vbulletin-formcontrols.css" there is only a definition for background

Block Disabled:      (Update License Status)
Suspended or Unlicensed Members Cannot View Code.

Two solutions:
A. Edit "vbulletin-formcontrols.css" to

Block Disabled:      (Update License Status)
Suspended or Unlicensed Members Cannot View Code.

B. Go to template "additional.css" and add

Block Disabled:      (Update License Status)
Suspended or Unlicensed Members Cannot View Code.

Change #888888 to a color of your choice.

[RGL Griff XV]

This worked perfectly, thank you