It's possible, but probably not advisable because the green drive will drag down the performance of the RAID set. If you want performance use two black drives. If you want low power / low heat dissipation, use two green drives.
...but using green drives for the OS will hurt performance.
I see.. assuming that i use 2 black drives. is it possible to partition both drives and put them in raid 1. like disk 1 partition A is mirrored by disk 2 partition A and disk 1 partition B is mirrored by disk 2 partition B?
if i use a black and a green drive and put them in raid 1, the green drive will become the bottleneck, is this correct?
You RAID the disk first, and then you partition it. So if you buy two 1TB drives and put them into a RAID 1 set, when you go to partition the drive (either as part of the Windows installation or via Disk Management for an already-installed system) you'll see what appears to be one 1TB drive.
And yes, in a RAID set with a black and a green drive the green drive will be a bottleneck.