The pic shows everything - 5 of each colour of gate. Hope that makes sense (the vid in the post directly above yours might help a bit too).
I know what you mean there, but by not *having* to ride a certain colour and easy red gates probably being about the same as hard blue gates, you do get the chance to try some, and by the end of the comp everyone finds their own level (in theory!). The scores should work out with the best riders (those who have cleared the highest number of harder gates) at the top of the score sheet, too. That in itself does create an issue though, it's very hard to classify riders, other than by wheel size and / or age.
We considered letting people ride as they want but we strongly feel that BIU makes trials look a bit shit. On the flip side, it's tricky for kiddies to ride UCI so you have to let them use pedals and bashes.