can i colour my hair now

Hi ladies

I have lot of grey hair so i was applying colour to it. my hair has become rough so today i applied shahnaz hussain heena to it. but only grey hair become reddish and the rest of the hair remained the same.

my question is can i apply colour to it again as it doesn't look nice. shall my grey hair gain the colour again as of now it is reddish??

Please answer my query?