GY3 is Curious Yellow / Citron Yella
GW3 is Brite White / Sno White
My printing of Galen's booklet shows the correct codes...
BTW - G = First year color offered (E=69,F=70,G=71,Etc)
W = Basic color (W=White,Y=Yellow,Etc)
3 = Color variant (higher numbers are generally darker shades)
Hope this helps,
XS