Add yoghurt to a large mixing bowl. If adding any flavourings and stir them through now, before the colouring.
Drop 2 drops of the black gel food colouring on top of the yoghurt.
Take a wooden skewer or a butter knife and gently swirl colouring into the yoghurt creating a marble effect, ensuring not to completely mix them together. NOTE: It will look like the colouring has just swirled on top of the yoghurt and not through the entire yoghurt, this is ok because you want more white than black.
Gently spoon yoghurt and divide yoghurt evenly into a 4-hole popsicle mould.
Place in freezer and freeze for 4-6 hours or ideally, overnight.
To remove, sit each popsicle mould in a jug of warm water until the popsicles slowly release from the moulds. Alternatively, place each one under running warm water until they release. Enjoy!