In some circles (not the seventh one), yes. But I think most teenage/adult beginners looking for a challenge could manage an orange course.
If you have lots of children turning up, and they haven't been trained in the secret arts, then you could be in trouble.
I guess it depends on how many events there are. If you have a family-friendly event every Sunday then adding experienced-only events on Saturdays would be grand. If you only have 20 events a year, you probably want many to be suitable for kids.
Certainly W/Y/O/Br/G/R/B all three days seems excessive for the TT weekend, but that was a precondition...