WoW, guys!
You left me speechless. I didn't expected such a response, I'm really glad you all like it.
The yellow chord has a very simple mix:
Base: Burnt Umber + Sunburst Yellow (Citadel)
1st Highlight: Pure Sunburst Yellow
Sucessive highligths: Sunburst Yellow + Ice Yellow
Shadows: base + Burnt Umber
Again, thanks all for your kind comments.
Regards
FeR