Most Shows class titles will be Skewbald and Piebald, or coloured now, with a note to say to include dun,palomino etc. If it doesnt have the note about duns etc, then it will probably still only be Piebalds etc :)
If you are only getting the vetting for insurance do they require 5 stage? Depending on what purpose you are getting horse for - and do say jumping or eventing if so, not just hacking! Could be anything from £100 - £300 I guess:confused: