Paraiso from Katia is a 100% cotton space dyed multi-coloured yarn.  There are 360m per ball and it sells for $18 each.  This yarn suggests using a 3.0 to 3.5mm needle size, so it's a sport weight yarn.  Perfect for summer clothing and accessories.  3 balls would make a nice t-shirt.  
 
Fibre Content:   100% Cotton
Weight:    Sport (#2)
Yardage:   360m/393yds in 100g ball
Gauge:    23sts + 30 rows with 3.5mm (US 4) needles
Care:   Machine wash in cold water,  gentle cycle