there is bro. but the pricing expensive. 30-50.
regarding yellowish issues.
i went MV/Gardens , 2 sony centres.
the curve / ecurve, 2 sony centres.
lowyat sony centres and some dealers.

all sets are yellowish.

from my experience, i opened up almost 5x of z1 of each branches.
ALL yellowish compared to some of the white screen demo units.

the curve sony centre has good service, 7 of their employees tried to solve my problem. YES SEVEN !

my verdict, all later batch are yellow but better viewing angles.
when u look straight to the phone, when its white, confirm side view will be yellow.
for straight up yellowish, side see will be white and clearer.
i spent 2days for this adventure hahaha.

but dont worry, the triluminous display color can be adjusted via updates or maybe custom kernels, or i'll find back that guy who told me so

Sony set come with black sticker