In a certain code language, if GREEN is coded as 1677209 , then how would BLUE be coded in that language ?

Alphabetical code for G = 7. Adding 2 will make it 9.
Alphabetical code for R = 18. Adding 2 will make it 20.
Alphabetical code for E = 5. Adding 2 will make it 7.
Alphabetical code for E = 5. Adding 2 will make it 7.
Alphabetical code for N = 14. Adding 2 will make it 16.

GREEN is coded as 1677209. This means that 2 is added in the alphabetical code of each alphabet, and then the entire order is reversed. 

Alphabetical code for B = 2. Adding 2 will make it 4.
Alphabetical code for L = 12. Adding 2 will make it 14.
Alphabetical code for U = 21. Adding 2 will make it 23.
Alphabetical code for E = 5. Adding 2 will make it 7.

Thus, BLUE is coded as 723144.