This is because all water-based materials have been removed and replaced with bake & cake friendly oils; these oils mix through much better than water-based gels (which we know water repels from the oils in your baking).
Sugarflair Mustard (Yellow) Oil Based Food Colouring, Highly Concentrated Edible Oil Based Blue Food Colour for Consistent Colouring of High Fat Foods: Icing, Buttercream, Chocolate & More - 30ml
Edible Food Colouring Mill Yellow Oil Based 20ml Cake Decorating Sugarcraft
Sugarflair Bumblebee (Yellow) Oil Based Food Colouring, Highly Concentrated 30ml
Colour Mill Oil Based Food Colouring Yellow - Next Generation Oil Based Food Colouring for Baking, Decorating, Icing and Cooking Food Dye DIY Slime and Crafts Making - 20 ml
PME Cake Oil Based Food Colour with Precision Dropper | Yellow (20ml) | High Pigment Oil-Blend Food Colouring for Buttercream Chocolate Ganache Fondant & Cake Batter
YELLOW Colour Mill Oil Based Food Colouring 20ml bottle cake decorating icing