I was confused by this, too.

Faded cards means the player has a booking, but it is not in the relevant upcoming match. Check a players stats section to see in which tournaments he is carded.

Double yellow leads to 1 game suspension for same tournament; straight red card leads to 2. In stats, the (1) or (2) by the red card symbol indicates how many suspended matches remain. Cards remain with the player until end of season or suspension had been completed.