|"Channel A is dimm A1 blue and dimm A2 black is this right for dual channel?"|
You want to run DUAL channel, that means A + B. If you use slots A1 + A2, they'll both be on channel A, therefore the RAM will run in single channel mode.
Since you're installing 4 sticks, there should be no problem, unless you have an older system that underclocks the RAM when all 4 slots are used?