WowAce

What version of Grid2 are you using?

 r849 Alpha

Since updating the entire health defecit turns bright white like the highlight on mouseover:

vs

 I can't seem to find the options to change this setting, after seeing a comment it was added in another ticket. Perhaps I'm just being completely blind?

- Go to  Themes -> Default -> General Tab -> Disable highlight or change the highlighth texture & color, the default highlight texture is "Blizzard Quest Title".

If you only want to highlight the frame border:

- Goto -> Indicators -> Health ->Layout Tab -> Check the "Enable Background" Option.

Ahh there it is, disabling the texture sorted it. Thanks!