>>25338958There are two ways to check how "rare" and good a pokemon is, by the stars notation(more stars the better, and pink>yellow), or by checking their quality(or QUA for short).
Pink 5* pokemons are 15 QUA, while Yellow 5* pokemons are 14 QUA. Some 14 QUA are useful because of their support skills(bonus to the team if the pokemon is in the support slot), but you will mostly want the 15 QUA pokemons.
Later on, on more finished teams, you will have 6* pokemons.