Nice one Ged, they can provide a colour to add to the sealant. The guy i spoke to was spot on & suggested that if the customer could live with it just to use a clear sealer but if it is really bad, as this one is in patches, just to use the coloured seal on the worst patches.
He does not recommend doing the whole area(in my case about 80m) as when the seal wears off the pic will look really bad.
He is sending me some info & i will let you know how it turns out if youre interested
Thanks again