Transmission fluid problem

I checked my transmission fluid because it hardly will shift from gear to gear unless accelerating real slowly. The trans fluid looked just below full but was black looking. Does anyone know the reason for this? My oil was also really dark even though I changes it a month ago.

I checked my transmission fluid because it hardly will shift from gear to gear unless accelerating real slowly. The trans fluid looked just below full but was black looking. Does anyone know the reason for this? My oil was also really dark even though I changes it a month ago.

Is the transmission slipping?
Lose of any gears?
Black as in or with burnt smell?
Was the filter changed with the fluid change.
Check for codes and drop the transmission pan and see what the filter looks like and if any clutches in the pan.