There are two arcs, one where she collects the cards, and one where she turns them into Sakura cards and Eriol-kun appears.
The first ones are a yellow color, and go through 6. The second arc has jewel like things in the corner...wah, thats a bad description, and say Cardcaptor Sakura (Mastor of the Clow). And goes through 6.
Yeah, I got confused and bout 2, 3 and 4 of the second arc and then 1, 5, and 6 of the first. A looooot of confusion, there.