Thank You Lynne,
It pays to come away from the pc for a short break.
When I use the "FireFox Bug" as suggested in that link, it shows the code as #a9a9a9 in the header (color).
It also shows this in the Header stylevar too (Please see attachment). It does not change the colour in the header (Background).
Any ideas please?
Many Thanks.
[EDIT] Cancel that - it was in: Header -> Header Background (Couldn't get in there, the first time around for some reason).
Thanks Again for all your help.