Original Green Drives....running slow...can I replace with equal Red Drives?

The unit is running real slow. I ran the Short Test Twice, Drive A failed on the first test, but passed on the second run. I am doing the long test now. These are the original green drives. Can I replace the Green drives with new Red Drives? Are the Red better? Is it time to retire the Duo Live? I have a Raid 1 going, so to transfer the data, do I just install the new drives and use a caddy to copy from the Green B drive to the Red Raid?

Due to limitations of the firmware on the My Book Live Duo, you can only replace with same for same drives. The Red drives will not work in that enclosure.

I ran the long test and the A Drive failed. So is this as simple as
disconnect the MBLD, replace the A Drive with the same Model Green
WD30EZRX, swapping the old for the new, turn the MBLD back on and it will
configure itself?