Perhaps we need some grade expansion.
as in more colour to further confuse people and for others to complain about? sounds like a very bad idea to me. the green-blue-red-black-orange system works perfectly well in ski resorts so why should it not at trail centres?
the main problem is that people compare centres to each other; what is black at a TC like degla for instance would only be a red at other places (especially scottish centres). but in terms of what is currently offered up at degla they have the main xc loop graded red, for it's distance and some technical sections, and then the additional black sections which are for more advanced riders. nothing wrong with how it's graded IMO.
having said that i've heard that the FC are curerntly looking at the grading system of all TC's in the UK and soon will formalise classifications based on the 1/2/3 traffic light like circles seen on the glentress FR park.