The spoiler on the Yellow IS is a Lexus front skirt (in Australia) suitable for the standard bumper.
Original Bumper
It is not a "Legana" front skirt. The Legana kit does not have a lower bumper skirt, but a complete front bar.
Legana Front Bumper
And the rear skirt is part of the Australian "Legana" kit.
Hope that helps :)
I actually don't have the rear skirt, its the rear wing I have on my tail, I'm thinking its a standard Lexus Australia part.....