Not sure about breeds but coloureds still seem to be very popular. I was looking though the For Sale section in H&H this morning and thinking how many there were (and how expensive ..)
Over here the heavy cobs seem to be all the rage, tbs seem to be on their way out, when we tried to sell our tb it took ages and was really difficult. With the cobs people are more worried about how quiet they are, with ozzy we found people looked into everything more, ie jumping, out on road, manners etc.
Definitely find it easier to sell a cob than a finer horse. Colours are definitely in, got loads of people looking to buy my girl angel and mia who are coloured.