"彩" being read as "Sayaka".. I guess hers is a so called キラキラ (Kira Kira) name?
Had to look that term ^ up
A new trend for children's names sweeping Japan is the "kira-kira name" phenomenon. "Kira-kira" literally means "shiny" or "sparkly" and what is going on is kids are getting shiny new names that look or sound cute or interesting, but are unintelligible to all but the kid's parents. The Chinese Kanji are being used as a phonetic symbol rather than for the meaning of the kanji. And names are being given that sound like characters from animation films or games. - See more at:
http://akihabaranews.com/2013/08/12/article-en/kira-kira-names-shiny-names-kids-chagrin-many-japan-1701127852#sthash.YOWAvUNM.dpufWhen first introducing herself in her NMB48 blog she wrote that her first name is "彩" (normally read as 'Aya') but pronounced as
'Sayaka'.
As the name Sayaka does not seem particularly "kira-kira" perhaps it is just an obscure secondary choice for that kanji, rather than a 'kira-kira' name?
Of course we could do what photographer Leslie Kee did-
use Romaji!