Thanks guys for the explanations.Here in Aus we have the same coloured plate front and rear. I can see how the different colours work now. Cheers to all!!!!
When I was in WA I had black on blue personal plates on my 110 , here in UK you cant have personal plates so there is a market in certain natural combinations that spell something eg COM 1 C some get a bit strained
see here Private Number Plates For Less
HTFH