RAM memory slot speed

[TheOliveDolphin]

I have an ASUS b85m-e mobo with 4 ddr3 memory slots but I only have two sticks of memory (Hynix 2x8gb @1600mhz) does it matter which slots I put them into? Should they be close together?

 

[Dark Lord of Tech]

Either in both black or both yellow.

A1 and B1 or A2 and B2.