I'm going to dye my hair at home... And I have no idea what I'm doing?

[summersxkiss]

Hi! 
 
I have brown hair (I think it's about a shade 5) and I had caramel highlights for the summer. Now that Autumn is almost here, I'd like to go back to a dark brown.
 
I have a few questions because I'm not that great at dying my hair :/
 
This is my hair colour at the moment:


 
The highlights are turning quite brassy, which I don't like. I wanted to go back to this type of dark black brown colour

 
Which is similar to my natural hair (although I think my natural hair is a little lighter) here: 

 
Which colour dye do you suggest? Somebody told me if I went ashy, the blonde parts of my hair would turn green... Which worries me a bit, lol
 
Should I use permanent or semi permanent dye? Will I get roots showing if I used permanent?
 
Thanks so much... If anybody has any tips I'd be so grateful <3
 
Rosie xxx
 
Edit: Removed links and added pictures.

 

[mistygem]

Even if you got permanent, eventually your roots will show. Hair dye, permanent or not, only affects the part of the hair that got dyed. When you grow your hair out, your natural hair color will start showing, it doesn't really matter if it's permanent or not. However, when you do go with semi-permanent hair dye, the color will probably be already gone before your roots become too obvious (so there's that). With permanent dye, if you want to avoid your roots showing, you may have to do some maintenance dyeing (which could be harsh for your hair).

Also, do take note that not all hair dyes are made equal. Some have chemicals that others don't. Before you proceed, make sure you do a skin test first (you can mix the dye and dab it on the back of your knee or in your elbow fold, let it dry for 30 mins, wash it off, then observe if you get an allergic reaction within the next 24 hours). This is important because you don't want your entire head/face swelling from an allergic reaction.