Exam help - in ca final exam can i write exam with gel pen

As in instructions to examee ICAI has written that answers Should be written by blue or black BALL POINT PEN.  Is writteng answers in gel pen is wrong ? Is there anyone who write exam in gel pen and not faced any problems from ICAI ? Please also suggest good gel pen if written answers in gel pen is allowed ? I think uni-ball eye is good gel pen what you think. Please also tell if gel pen allowed and I decided to write exam in blue gel pen but in market most of blue gel pen are sky blue colour blue pen , is that sky blue colour pen is allowed as BLUE PEN in exam ?