The FINAL FMA in blue - a MAN/MAN approach has been selected in the MCDU and the pitch is armed to maintain the final descent profile. (You won’t see a FINAL FMA when flying an ILS approach.) Other FMA’s you will see on a MAN/MAN approach are APP NAV (blue - lateral guidance armed) APP NAV (green - lateral guidance engaged) and FINAL APP (green - vertical and lateral guidance engaged) Some other FMA combinations you may see are pictured as well.
RWY FMA (green) is for T/O. If takeoff runway has a localizer it is autotuned. You’ll see a ground roll guidance bar on your PFD during the takeoff roll until 30’ AGL. (And you know I just read somewhere when that appears when taking the runway but now I can’t find it - so I’ll go with your 20 degrees)
