Complete the following events for stars (in any order): Beat the Elite Four; Defeat Red; Win 100 consecutive battles in Battle Tower; Show Hibiki 5 Gold Leaf pokemon; Capture all 493 Pokemon (does not include event-only pokemon). The number stars you have determines your Trainer Card color.

Red Card - Default
Blue Card - Obtain 1 star
Bronze Card - Obtain 2 stars
Silver Card - Obtain 3 stars
Gold Card - Obtain 4 stars
Black Card - Obtain all 5 stars