I couldn't find much info on either of these. The most I could find was what the FRLG FAQ said about the trainer cards, but even it doesn't have everything. If you have any info on these, I'd appreciate if you'd post.

Trainer Cards:
Blue - Start the game.
Green - Beat the Elite Four
Bronze - Catch 150 Pokemon (The first 150 Pokemon?)
Silver - Catch all Pokemon except Mew, Celebi, Deoxys, and Jirachi.
Gold - 200 jumps and 200 berries caught in the games room
Platinum - Doesn't exist.

Stickers:
Eggs:
Lv1 - Hatch 1
Lv2 - Hatch 100
Lv3 - Hatch 200
Lv4 - Hatch 300
Hall of Fame:
Lv1 - Win 1 time
Lv2 - Win 40 times
Lv3 - Win 100 times
Lv4 - Win 200 times
Link Battle:
Lv1 - Win 1 time
Lv2 - Win 20 times
Lv3 - Win 50 times
Lv4 - Win 100 times
Not sure about the color on the stickers. If someone could confirm them for me, that'd be great.

Highest trainer card in FRLG is a four star gold card (there's no platinum) - you get the last star by jumping 200 times in Pokemon Jump mini-game (check Two Island) and getting 200 berries in Dodrio berry picking mini-game

If there's no platinum someone should tell an admin so they can fix the FAQ.

Thanks for the info.