Mega Marbles Fun 1/2 Inch Peewee Set of 24 Assorted Styles

I am looking for an assortment of marbles for a ring that only holds 12mm or 1/2" marbles. Are these that size?

Are these marbles all 12mm?

I need several sets of 5 marbles. Marbles in each set must be same color, but each set needs to be its own, unique color. Will this assortment work?

Are these marbles small enough for a marble run game?