Philippe, your question made me look further in to the parantage of this and I've spent the last two hours on the RHS website working out exactly what is in it.
Turns out that while it's a pretty complex hybrid it is over 50% sanderiana, and that parent definately comes through in the look. It actually all boils down to just 5 species...
sanderiana 59.96%
coerulea 25.39%
luzonica 7.81%
dearei 3.91%
tricolor 2.93%
I've attached an image of my spreadsheet where I layed out the exact parantage to calculate this. I know... I'm a bit of a geek