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).
Colour Flex Black Oil-Based Food Colouring 25ml - Vibrant Concentrated Formula for Chocolate, Buttercream, Cake Batter and More by Sugarflair - Vegan, Kosher, Bake-Stable
Edible Food Colouring Mill Black Oil Based 20ml Cake Decorating Sugarcraft
Edible Food Colouring Mill Black Oil Based 100ml Cake Decorating Sugarcraft
Colour Mill Oil Blend Food Colouring Black: Next Generation Oil Based Food Colours - 20 ml
Colour Mill Oil Blend Food Colouring Black: Next Generation Oil Based Food Colours - 100 ml
PME Cake Oil Based Food Colour with Precision Dropper | Black (20ml) | High Pigment Oil-Blend Food Colouring for Buttercream Chocolate Ganache Fondant & Cake Batter