This is a 3 Ingredient Recipe for the noodles. All you need for just the noodles are:
purple cabbage
glass noodles (mung bean noodles)
lime or lemon juice
To get the blue/purple/pink noodle colors, all you do is vary the amount of water used, the time the noodles are in the colored water, and add lime or lemon juice for pink noodles.