The video bellow will show you how to change colors when working in the round.
If you are going to use that same color again don't cut the yarn that goes to the ball, just leave it on the inside of the work and pick it up again when you need it.
YARN: Crochet thread size 5 (0: Lace). More info here: http://bit.ly/2O10RyT YARDAGE / GRAMS: Less than 200 yards / 50 grams of (color/s of your choice). HOOKS: 2.25 mm (B/1) crochet hook. GAUGE: 33 sc and 15 rows= 4 inches (10 cm)
Crochet thread size 5 for the coaster / Light fingering yarn for the placemat.
More info about yarn here: http://bit.ly/2O10RyT YARDAGE / GRAMS:
White: less than 3g for coaster / less than 50 g for placemat. Red: less than 3g for coaster / less than 50 g for placemat. Black: less than 1g for coaster / less than 10 g for placemat. HOOKS: