If colouring white fondant, use a toothpick to add a small amount of colour to the fondant and knead on a benchtop until the colour is evenly distributed and the fondant is the desired colour.
Lightly sprinkle icing sugar onto the benchtop and roll out the fondant until it is very thin.
Using a piping nozzle cut out the sprinkles.
Repeat with as many size/shaped cutters and with as much fondant as you like.
Spread the sprinkles out on a tray lined with baking paper and leave out until hard - I left them overnight.
Transfer to an airtight container and store for months.