I run the standard (yellow) spring and I weigh 68kg personally i feel its the perfect setup. Because if you run a soft spring it makes it harder to pedal, bottoms out going around corners and it its harder to carry speed. To make the forks perform better use 3 clicks of compression. And if your using boxxer race forks you are probably better off buying boxxer team internals for $180 because its got the the high speed compression which makes a big difference on the fast rocky tracks like thredbo.
I'm 93kg and run a yellow spring (sometimes red/firm if I want the front end to stand up a bit more or the track is very jumpy). There is no way that you should be on a spring that stiff at your weight, the stock springs are suitable for riders from about 85 to 100kg. If you're bottoming out a yellow spring going around corners, you're either hitting corners at Sam Hill speed with no finesse at all or, well, you're not actually bottoming out. Also, 3 clicks of compression on the Motion Control damper does nothing at all that I can tell, 4 gives you a bit of damping, 5 is tons, 6 is almost locked out and 7 is actually locked out.
You can modify Races very cheaply/easily to work as well as Teams, the only disadvantage is that you can't adjust the floodgate externally. Do a search for "boxxer nut mod" and you should find it.
Viv, you should be on a soft spring (silver I believe?).