Suppose, say, one die is red and the other green.
Here are all the possible rolls with a red die and a green die:



(1,1) (1,2) (1,3) (1,4) (1,5) (1,6)
 
(2,1) (2,2) (2,3) (2,4) (2,5) (2,6) 

(3,1) (3,2) (3,3) (3,4) (3,5) (3,6)
 
(4,1) (4,2) (4,3) (4,4) (4,5) (4,6)
 
(5,1) (5,2) (5,3) (5,4) (5,5) (5,6)
 
(6,1) (6,2) (6,3) (6,4) (6,5) (6,6)

There are 36 possible rolls. The only rolls with have sum 11
are (5,6) and (6,5) So there are only 2 possible rolls out of
the 36 which have that property.

Therefore the probability is  
which reduces to  = 0.056

Edwin