These were actually all digitally recoloured using Photoshop because I didn’t want to paint so many parts specifically for these characters for them to lose - though now that one of them is going to be the officially recognized depiction of the character, I definitely want to finish the job and paint him for real.
I don’t have an exact match, but from others’ experimentation, it seems that 1-to-5 of Citadel “Slaanesh Grey” and Turbo Dork “Blue Steel” is really close.
The official colour could definitely be changed by the end of the next half of the contest… but even if it is, and you prefer blue (like me!) no one’s gonna stop you from painting your own whatever colour you want to see 
Thank you!
The Mask of Sensory Aptitude happens to be my favorite canon mask design, and I think it pairs nicely with the other parts I used. I also really like how he’s got eye pieces - continuing the trend set by Nuju and Kopaka before him (or after him, story-wise…), but without just rehashing an asymmetrical, scoped mask design for a Toa of Ice again.
So I for one am super pleased with the mask! 
I could be wrong, but I don’t believe either of the mask designs you shared were permitted for this contest?
They are still very cool designs nonetheless, especially that first one. I could easily see it being used in someone’s fanon as the traditional shape of the Mask of Rahi Control before Kualus’ former teammates reforged it to honour someone who’d worn a Sensory Aptitude mask.