Olia garnier hair dye and manic panic !?

I attempted to colour my hair a dark garnet red colour with olia garnier hair dye. There is no ammonia in it but apparently its supposed to turn out ....a dark red. Well..it didnt. So...i seen a review on youtube where a lady went over her already dyed hair (which was dyed by olia garnier) with a red in manic panic and it turned out really nice..but the washout and application is really messy... So i was wondering if any ladies have any advice on diy ???