1asoundasleep- 777 sliderafts are large, silver in color and rectangular. Aviation liferafts of the hexagonal shape (Goodrich brand iirc) are bright yellow. A slideraft gets any yellow/orange colour from the canopy which is separate and would be erected by the crew once the raft is seaworthy.
As for provisions, it would totally depend on the amount of people in each slideraft, time adrift, etc... I believe two weeks would not be out of possibility but tbh I've never seen quantities listed in my manual... only general list of items.