Looks amazing

Thanks ^^
I hope the final product will work as I have planned. It's been too long since I picked up a pencil

Doesn't look like time has done anything to diminish your ability

Mainly in the anatomically correct department. Out of many attempts this is the first sketch that feels like it makes sense. Thank you for the compliment though ^^

What do you use to achieve such a tremendous iridiscent effect!? / ¿¡Qué usas pa' lograr este efecto iridiscente tan tremendo!?

Unfortunately I can't truly explain, because I go by trial and error/feel. But I'll try: I use Prismacolor pencils, their pencils tend to be soft and blend nicely. I used... roughly 3 different blues, a light green and very dark green, and some black to increase contrast.
Then I really just looked at pictures of birds with this iridescent feathers and try to replicate the effect with the pallet I have available.