Where to put ram to get dual channel at GA-Z77X-D3H

hi guys
if you look at pic of GA-Z77X-D3H you will see that all 4 ram slots are black
in manual it says to get duel channel to put them in 2 of same colors but mine are all 4 black so i have no idea what they mean by that.. by looking some other mb's i noticed they have 2 blue sockets and 2 white or so, so i get it how it works there, but mine are all 4 black
there is in guide numbers near momory slots, like

4-2 3-1

so 4-2 are to the left 2 slots together, and 3-1 are other 2 slots together. so do i put them in 2 1 with one slot empty in between them or do i put them right next to each other?
pic to make it more clear
http://imageshack.us/photo/my-images/221/87380911.png/


i never before done this and no matter how stupid i think my question is i really think its better to ask than to make some mistake and maybe dmg something
so how do i combo them
solution on my picture no 1., 2., 3. or 4.?
thanks for reading