Safin

Always use the semi's that way it fades out rather than have a line of regrowth. I've found the permanents fade almost as quickly out here but leave a line and they go orange in the sun (usually use a mid brown).
When the last lot of permanent growns out I'm going to try the highlighting route instead.

Claire W

New hair growing through grey is usually courser than hair before it loses it's pigment and this is why it tends to "stick up" from the rest on the parting area.
I would recommend going for colours lighter than med.brown unless you want to be very dark.....dark blonde is only a shade off being light brown !!
I've lost count of how many people have said " it was only supposed to be med. brown it looked black !!
Also you have to watch texture of hair as to how much it will grab , how much natural red or ash is in it etc. etc....so I would say if you do your own and get away with it you are luckier than some ....especially the home highlighting kits....I think they're the scariest thing invented...in the hair colour world !!
Good luck
Claire