^^sis, how did u do it? I mean, twice na ako nag DIY, actually my tita applied it sa hair ko. Pero laging hindi pantay color

bra-length hair ko..
So i bought hortaleza hair color sa HBC, mix ng 12%, tapos she applied it, unang lagay sa roots muna (since i previously had my hair color sa salon.. ngayon lang ako nag cost-cutting :p ) so babad ng 30 min sa roots then kinulay na nya yung remaining hair then babad again for 30min
Sa first week, ok pa, until unti unti nagfade yung color (which is ok w/me) at lumalabas na yung hndi pagkapantay. Bale 1inch from the roots, ok color, then after that mga 2 inches a little bit darker then after that, ok na kakulay na ng roots yung remaining of the hair.
Pero this one more obvious sa left side ng head ko.
So naisip ko since hindi naman experienced tita ko, after a month, pinacolor ko ulit, sa HBC ako bumili (yung ammonia free), free application sila, so i guess may experience naman tong si ate HBC, kaya medyo confident ako.. Kaso after a week ulit, ayan na lumalabas na yung obviousness, same case nung una..
Hindi naman tinipid yung gamot, kasi may sobra pa nga nung una and yung 2nd time na i tried DIY.. Pero bakit ganun hindi pa rin nagpapantay?
Kung i will buy sa HBC ulit, then have it colored sa salon near my place for a fee (php350 when i asked), hesitant ako baka same effect din..
i really like the color sa HBC kasi if sa cheap salon ako baka ibang brand gamitin sakin and i wont get the hair color i want.. Please help!

ok.. i know i wouldnt have this experience if sa magandang salon ako pupunta or sa dating salon na pinupuntahan ko., but then i really want this DIY hair color to work on me...