It's clear that in all the alpine skiing events you need to go from red gate to blue gate and you need to go round them. I cannot understand fully that in the slalom race. Most of the gates there, have some distance between them, but sometimes the red and blue gate are right one after another. Are they counted the same way, or the rule for those close gates is different?
Also in slalom skiiers has to pass alternatively in red gate then blue gate.
In every speciality skiiers make inspections (mostly with thier trainers) before the races to check and study the structure of the tracks
When the gates are placed in position "perpendicular" to the descent is easier to understand the succession of the gates, but it can happen that the gates are placed in a "parallel" way to the descent and in this case the skier has to turn close to them.
When two ports are very close succession of uses "double" term to describe this figure as if it is three doors in close succession using the term "triple" (this is a translation from Italian language).
From the logical point of view there are no differences from the "perpendicular" tracking, but visually understanding is more difficult.
In downhill they test the track with time trials twice before every race (in the image you can see the FIS calendar for december 2015 where all the time training downhill are signed with blue arrows)