Our Breed Council organises breed seminars in the UK for aspiring judges which they have to pass to progress up the judging lists (I was an assessor at the last one and am a KC approved judge for Basenjis). The colours are definitely gone through thoroughly and we try to have representatives of at least the main four colours, though the brindles and especially blacks are very thin on the ground and Ruby and Bryn have done sterling service as colour reps! At the last seminar there were examples of both regular and barred tris. At the moment we have no recessive blacks in the show ring and rarely do, but the colour is mentioned in the presentation with an explanation of how it tends to change with age. There has not been a trindle shown here to the best of my knowledge so we have yet to tackle that thorny issue. The BC presentation emphasises clear, rich, well-demarcated colours.
Naturally some judges see colour as more of a priority than others. I do try to ensure that there is a b/w at the seminars if at all possible, as many upcoming judges may never have seen one and probably never gone over one.